Displaying publications 1 - 20 of 50 in total

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  1. Nordin R, Hamid AM, Adnan WA
    World Health Forum, 1992;13(4):300-2.
    PMID: 1466724
    In Malaysia the steady rise in the proportion of people aged 60 or more, and an awareness of their complex psychosocial, economic and health care needs, have led medical faculties to introduce geriatrics as an essential subject in their curricula. The efforts made in this field by the School of Medical Sciences of the Universiti Sains Malaysia are outlined in the present article.
  2. Ramli R, Che Man Z, Nordin R, Abdul Karim F, Rashdi MF, Oxley J, et al.
    Traffic Inj Prev, 2016 Sep;17 Suppl 1:79-85.
    PMID: 27586107 DOI: 10.1080/15389588.2016.1203428
    OBJECTIVE: Vietnamese spend hours travelling on the road using their motorcycles. Their helmets are exposed continuously to sunlight and rain. The objectives of this study were to determine the association between the effect of photo-oxidative degradation (POD) of the outer shells and helmet age on helmet damage. The micro-structural change of the outer shell was also investigated.

    METHODS: This was a prospective, cross sectional study recruiting injured motorcyclists from Hanoi, Vietnam hospital. The participants were interviewed by a trained researcher. The participants' helmets were collected post-crash. Initially, the helmets were examined for their type and external characteristics. A 3 cm × 3 cm cut was made on the helmet in the impacted and non-impacted areas (control). These areas were investigated for evidence of POD and presence of micro-cracks and material disintegration. 50 participants were enrolled. Sources of information included questionnaire and laboratory analyses. The helmet factors of interest were age of the helmet, exposure of helmet to sunlight and rain (duration/day) and history of previous impact. Laboratory analyses included Fourier Transform Infra Red (FTIR) for degradation and scanning electron microscopy (SEM) for micro-structural examination.

    RESULTS: Majority of the helmets was the open-face type, 40 (80.0%). 31 (62.0%) helmets aged less than three years (LTY) and 19 (38.0%) were three years old or more (MTY). 19 (61.3%) of the LTY helmets and 12 (63.2%) MTY helmets showed evidence of POD. The duration of helmet exposure to sunlight was between 93 to 6570 hours (mean 2347.74 hours; SD 1733.39). The SEM showed 15 helmets (30%) with micro-fractures, 21 helmets (42.0%) with material disintegration. Prolonged uv exposure to the ABS helmets resulted in changes in the helmet material in the form of material disintegration and microcracks and this association was statistically significant (p = 0.03).

    CONCLUSION: POD occurs due to routine exposure to the ultraviolet light. Prolonged uv exposure affects outer shell surface material integrity.

  3. Al-Haiqi A, Ismail M, Nordin R
    ScientificWorldJournal, 2014;2014:969628.
    PMID: 25295311 DOI: 10.1155/2014/969628
    Covert channels are not new in computing systems, and have been studied since their first definition four decades ago. New platforms invoke thorough investigations to assess their security. Now is the time for Android platform to analyze its security model, in particular the two key principles: process-isolation and the permissions system. Aside from all sorts of malware, one threat proved intractable by current protection solutions, that is, collusion attacks involving two applications communicating over covert channels. Still no universal solution can countermeasure this sort of attack unless the covert channels are known. This paper is an attempt to reveal a new covert channel, not only being specific to smartphones, but also exploiting an unusual resource as a vehicle to carry covert information: sensors data. Accelerometers generate signals that reflect user motions, and malware applications can apparently only read their data. However, if the vibration motor on the device is used properly, programmatically produced vibration patterns can encode stolen data and hence an application can cause discernible effects on acceleration data to be received and decoded by another application. Our evaluations confirmed a real threat where strings of tens of characters could be transmitted errorless if the throughput is reduced to around 2.5-5 bps. The proposed covert channel is very stealthy as no unusual permissions are required and there is no explicit communication between the colluding applications.
  4. Amin NA, Quek KF, Oxley JA, Noah RM, Nordin R
    Int J Occup Environ Med, 2015 10;6(4):232-42.
    PMID: 26498051 DOI: 10.15171/ijoem.2015.632
    BACKGROUND: The Job Content Questionnaire (M-JCQ) is an established self-reported instrument used across the world to measure the work dimensions based on the Karasek's demand-control-support model.

    OBJECTIVE: To evaluate the psychometrics properties of the Malay version of M-JCQ among nurses in Malaysia.

    METHODS: This cross-sectional study was carried out on nurses working in 4 public hospitals in Klang Valley area, Malaysia. M-JCQ was used to assess the perceived psychosocial stressors and physical demands of nurses at their workplaces. Construct validity of the questionnaire was examined using exploratory factor analysis (EFA). Cronbach's α values were used to estimate the reliability (internal consistency) of the M-JCQ.

    RESULTS: EFA showed that 34 selected items were loaded in 4 factors. Except for psychological job demand (Cronbach's α 0.51), the remaining 3 α values for 3 subscales (job control, social support, and physical demand) were greater than 0.70, indicating acceptable internal consistency. However, an item was excluded due to poor item-total correlation (r<0.3). The final M-JCQ was consisted of 33 items.

    CONCLUSION: The M-JCQ is a reliable and valid instrument to measure psychosocial and physical stressors in the workplace of public hospital nurses in Malaysia.

  5. Amin NA, Quek KF, Oxley JA, Noah R, Nordin R
    Int J Occup Environ Med, 2018 04;9(2):69-78.
    PMID: 29667644 DOI: 10.15171/ijoem.2018.1158
    BACKGROUND: Emotional distress is becoming a great concern and is more common in both developed and developing countries. It is associated with several disease conditions.

    OBJECTIVE: To determine the prevalence of self-perceived emotional distress and its relation to work-related musculoskeletal disorders (WRMSDs) in nurses.

    METHODS: A self-administered questionnaire survey was carried out on 660 female nurses working in public hospitals in the Klang Valley, Malaysia. The validated Malay version of the standardized Nordic musculoskeletal questionnaire (M-SNMQ) was used to identify the annual prevalence of WRMSDs; perceived emotional distress was assessed using the validated Malay short version, depression, anxiety, and stress (M-DASS) instrument. In addition, socio-demographic and occupational profiles of the participants were considered. Factors associated with WRMSDs were identified using logistic regression analysis.

    RESULTS: A total of 376 nurses completed the survey (response rate 83.3%). 73.1% of the nursing staffs experienced WRMSDs in at least one anatomical site 12 months prior to the study. 75% of nurses expressed emotional distress. Of these, over half also reported anxiety and stress. Multiple logistic regression analysis showed that stress and anxiety significantly increased the risk of WRMSDs by approximately twofold.

    CONCLUSION: There were significant associations between emotional distress and WRMSDs. Future longitudinal studies are therefore needed to investigate and identify the sources of emotional distress (non-occupational and occupational) to be used to establish preventive strategies to reduce the risk of WRMSDs.

  6. Liaw YY, Loong FS, Tan S, On SY, Khaw E, Chiew Y, et al.
    Breast J, 2020 Mar;26(3):469-473.
    PMID: 31486157 DOI: 10.1111/tbj.13520
    Women with a positive family history of breast cancer are greatly predisposed to breast cancer development. From January 2007 to December 2016, 1101 patients with a histologically confirmed breast cancer were divided into two groups: patients with and without a positive family history of breast cancer. Variables including age at presentation, ethnicity, tumor size, age at menarche, age at menopause, oral contraceptive pill (OCP) use, hormone replacement therapy (HRT), alcohol intake, smoking, body mass index (BMI), diabetes mellitus, parity, and breastfeeding were recorded. One hundred and fifty-nine out of 1101 (14.4%) of the patients had a family history of breast cancer. There was no significant difference in the incidence of breast cancer among Malays, Chinese, and Indians. Both patient groups presented at a mean age of about 60 years (+FH 60; -FH 61.2 P-value = .218). Significantly higher prevalence of history of benign breast disease (11.3%, P .018), nulliparity (13.2%, P .014), tumor size at presentation of more than 5 cm (47.3%, P 0.001), and bilateral site presentation (3.1%, P 0.029) were noted among respondents with a positive family history of breast cancer compared to those with a negative family history of breast cancer. The odds of having a tumor size larger than 5cm at presentation were almost two times higher in patients with a positive family history as compared to those without a family history (adjusted OR = 1.786, 95% CI 1.211-2.484) (P-value .003). Women in Malaysia, despite having a positive family history of breast cancer, still present late at a mean age of 60 with a large tumor size of more than 5 cm, reflecting a lack of awareness. Breastfeeding does not protect women with a family history from developing breast cancer.
  7. Abdul Hadi A, Naing NN, Daud A, Nordin R, Sulong MR
    PMID: 20578472
    The teaching profession is an occupation at high risk for stress. This research attempted to determine the prevalence of stress and the associated factors contributing to stress among teachers in Malaysia. A cross-sectional study was conducted on 580 secondary school teachers in Kota Bharu District. The instrument used to carry out the study was adopted and modified from the Depression, Anxiety and Stress Scale (DASS 21) and Job Content Questionnaire (JCQ). The questionnaire consisted of two parts: Part I consisting non-job factors (socio-demographic characteristics) and Part II consisting of psychosocial factors contributing to stress. Simple and multiple linear regression analysis were carried out. The prevalence of stress was reported as 34.0%. Seventeen point four percent of teachers experienced mild stress. Age, duration of work and psychological job demands were significantly associated with stress level. This study indicates job-related factors did not contribute much to stress among secondary school teachers. Non-job-related factors should be further studied to determine methods for stress reduction in teachers in Malaysia.
  8. Hadi AA, Naing NN, Daud A, Nordin R
    PMID: 17333785
    This study was conducted to assess the reliability and construct validity of the Malay version of Job Content Questionnaire (JCQ) among secondary school teachers in Kota Bharu, Kelantan. A total of 68 teachers consented to participate in the study and were administered the Malay version of JCQ. Reliability was determined using Cronbach's alpha for internal consistency whilst construct validity was assessed using factor analysis. The results indicated that Cronbach's alpha coefficients revealed decision latitude (0.75), psychological job demand (0.50) and social support (0.84). Factor analysis showed three meaningful common factors that could explain the construct of Karasek's demand-control-social support model. The study suggests the JCQ scales are reliable and valid tools for assessing job stress in school teachers.
  9. Naing L, Nordin R, Musa R
    PMID: 11944730
    Increasing risk of HIV infections among health care workers has been a continuing concern. The study was designed to identify the compliance of glove utilization, and factors related to non-compliance. A sample of 150 staff nurses were recruited from the study population of 550 nurses in Hospital Universiti Sains Malaysia. Data were collected by using a structured self-administered questionnaires. The response rate was 98.4%. The study revealed a low compliance (13.5%) of glove utilization (for all 9 procedures), which varied among different procedures (27-97%). Younger nurses and those with shorter duration of working experience had better knowledge of Universal Precautions. Nurses in intensive care unit and operation theatre were better in both knowledge and compliance of glove utilization. The three commonest misconceptions were identified as "selective use of gloves for high risk groups and suspected cases", and "tendency to depend on HIV prevalence". Nurses reported practical problems including administrative and personal related such as "stock irregularity" (46%), "glove not available at the emergency sites" (44%), and "reduction of tactile sensation" (39%). It was concluded that poor knowledge and practical problems were possible responsible factors for the low compliance. A good training for nurses comprising principle and practice of Universal Precautions, updated knowledge of blood and body fluid borne infections and risk and its management, will probably improve the compliance.
  10. Roslani AM, Sein KT, Nordin R
    Med J Malaysia, 1989 Mar;44(1):75-82.
    PMID: 2626116
    The Phase I and Phase II undergraduate teaching programmes of the School of Medical Sciences were reviewed at the end of the 1985/86 academic year. It was found that deviations from the School's philosophy had crept into the implementation process. Modifications were therefore made in Phase I and Phase II programmes with a view to:--(i) reducing content, (ii) promoting integration, (iii) improving clinical examination skills of students, and (iv) providing more opportunities to students for self learning, reinforcement and application of knowledge. The number of assessment items in Phase I and the frequency of assessment in Phase II were also found to be inappropriate and so modifications in assessment were made to rectify this situation.
  11. Ang KP, Nordin RB, Lee SCY, Lee CY, Lu HT
    Med J Malaysia, 2019 02;74(1):51-56.
    PMID: 30846663
    INTRODUCTION: We aim to study the diagnostic value of electrocardiogram (ECG) in cardiac tamponade.

    METHODS: This study was a single centre, retrospective casecontrol study. We recruited 42 patients diagnosed with cardiac tamponade of various aetiologies confirmed by transthoracic echocardiography and 100 controls between January 2011 and December 2015. The ECG criteria of cardiac tamponade we adopted was as follows: 1) Low QRS voltage in a) the limb leads alone, b) in the precordial leads alone or, c) in all leads, 2) PR segment depression, 3) Electrical alternans, and 4) Sinus tachycardia.

    RESULTS: Malignancy was the most common causes of cardiac tamponade, the two groups were of similar proportion of gender and ethnicity. We calculated the sensitivity (SN), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of each ECG criteria. Among the ECG abnormalities, we noted the SN of 'low voltage in all chest leads' (69%), 'low voltage in all limb leads' (67%) and 'sinus tachycardia' (69%) were higher as compared to 'PR depression' (12%) and 'electrical alternan' (5%). On the other hand, 'low voltage in all chest leads' (98%), 'low voltage in all leads' (99%), 'PR depression' (100%) and 'electrical alternans' (100%) has highest SP.

    CONCLUSION: Our study reaffirmed the findings of previous studies that electrocardiography cannot be used as a screening tool for diagnosing cardiac tamponade due to its low sensitivity. However, with clinical correlation, electrocardiography is a valuable adjuvant test to 'rule in' cardiac tamponade because of its high specificity.

  12. Mohamed N, Nordin R
    Malays J Med Sci, 2004 Jul;11(2):12-8.
    PMID: 22973122
    Many published studies that examined the effect of lead exposure on neurobehavioral performances were conducted in confined manufacturing environment with low to moderate blood lead levels as a marker of exposure. This study was conducted in a general environmental setting with very low exposure intensity and blood lead levels. The objective of the study was to determine the effect of very low blood lead levels (below 10 μg/dl) on the neurobehavioral performances of policemen in Kota Bharu, Kelantan. The study, conducted between August 25(th) and October 20(th) 2001, was cross-sectional in design and comprised of 89 policemen working in Kota Bharu district. The lead concentration of venous blood was determined using graphite furnace absorption spectrometer. We assessed neurobehavioral performances using the WHO Neurobehavioral Core Test Battery (NCTB). The mean blood lead concentration was 2.5 + 1.0 mg/dl. Among the seven tests performed, the positive effect of blood lead on Benton visual retention was not significant after controlling for the confounding effect of smoke-dose. This study suggested that very low blood lead levels have no significant effects on the neurobehavioral performances. Therefore, more studies with blood lead levels below the recommended environmental limit of 10 mg/dl, as recommended by Centers for Disease Control (CDC), be conducted in order to justify that limit.
  13. Nordin RB, Rahman Bin Isa A, Rusli Bin Abdullah M
    Malays J Med Sci, 2001 Jul;8(2):9-13.
    PMID: 22893754 MyJurnal
    The prevalence of sexually transmitted diseases (STD) among female drug abusers was studied by screening 130 new inmates of a rehabilitation centre. Data was collected using a structured questionnaire, physical examination and specimen collection for laboratory investigation at the Community Medicine Clinic of HUSM. The majority (64.6%) were Malays and self-confessed sex workers (77.7%). A high prevalence of syphilis (50.8%), hepatitis B (52.2%), moniliasis (23.8%), trichomoniasis (19.2%) and gonococcal vaginitis (8.5%) was noted. More than half of them harbour 2 or more STDs. Six subjects, of whom 5 were Malays, were HIV positive. The evidence indicates that female drug abusers need a thorough screening for STD followed by an aggressive treatment regimen. Since the majority of them were born Muslims, they should have access to spiritual counselling and rehabilitation, stressing on repentance, and adopting a compassionate and forgiving approach.
  14. Bin Nordin R, Araki S, Sato H, Yokoyama K, Bin Wan Muda WA, Win Kyi D
    Malays J Med Sci, 2001 Jan;8(1):1-10.
    PMID: 22973149 MyJurnal
    To identify gender difference in safe and unsafe practice of pesticide handling in tobacco farmers of Malaysia, we conducted a 20-item questionnaire interview on storage of pesticide (4 questions), mixing of pesticide (3 questions), use of personal protective equipment and clothing while spraying pesticide (7 questions), activities during and after spraying of pesticide (5 questions), and maintenance of pesticide sprayer (1 question) in 496 tobacco farmers (395 males and 101 females) in Bachok District, Kelantan, Malaysia. Duration of employment was significantly longer in females than those in males (p<0.001). In addition, proportion with no formal education in females was significantly higher than those in males (p<0.05). The following eight common factors were extracted from the 20 questionnaires by principal components factor analysis after varimax rotation in all farmers: (1) use of personal protective equipment, (2) unsafe work habit, (3) reading and following instructions on pesticide label, (4) security, storage and disposal of pesticide container, (5) safe work habit, (6) proper handling of pesticide and maintenance of pesticide sprayer, (7) use of personal protective clothing, and (8) safe handling of pesticide. Results of analysis of covariance for the eight factor scores of all male and female farmers, controlling for educational level and duration of employment, showed that: (1) factor scores for use of personal protective equipment (p<0.001), use of personal protective clothing (p<0.001) and safe work habit (p<0.001) in females were significantly lower than those in males; (2) conversely, factor scores for reading and following instruction on pesticide label (p<0.001) and proper handling of pesticide and maintenance of pesticide sprayer (p<0.01) in males were significantly lower than those in females; and (3) there were no significant differences in other three factor scores (p>0.05). We therefore conclude that: (1) for female tobacco farmers, choice of personal attire tend to result in lower scores on use of personal protective equipment and personal protective clothing while personal hygiene practices result in lower score on safe work habit; and, (2) for male tobacco farmers, the lower scores on reading and following instruction on pesticide label and mixing pesticide and maintenance of pesticide sprayer in good condition suggests that they were not primarily involved in these activities. It is postulated that these differences in safe and unsafe practices of pesticide handling across gender is related to the choice of personal attire, personal hygiene practices and division of labour within farming households which in turn is influenced by prevailing sociocultural norms in the community.
  15. Nazimi AJ, Rajaran JR, Nordin R
    J Craniofac Surg, 2019 Oct;30(7):e609-e611.
    PMID: 31503125 DOI: 10.1097/SCS.0000000000005617
    Orbital blowout fractures are common. The same goes for its surgical complications when the efficiency of the dissection of entrapped or herniated intraorbital contents into the fracture could not be completely and safely dissected out. The authors describe a modification of the commonly used Howarth periosteal elevator for dissection of intraorbital content displacement or herniation on orbital blowout fracture. The instrument was modified by marking out the instrument from the tip into 10, 20, 25, 30, and 40 mm on both of its concave and convex surfaces to allow safe orbital soft tissue dissection and distance control. From the authors' experience, these simple modifications from its original instrument design allow better intraoperative control and appreciation of any intact important intraorbital anatomical structures such as inferomedial strut and posterior ledge. At the same time of importantly getting complete orbital fracture dissection and visualization, it causes less trauma to surrounding soft tissue with the markings ensuring unnecessary orbital exploration or visualization. Dissection can be kept for optimum maneuverability at the required or intended location based on the preoperative scan or dimension of anatomical orbital implant.
  16. Ibrahim N, Nazimi AJ, Ajura AJ, Nordin R, Latiff ZA, Ramli R
    J Craniofac Surg, 2016 Jul;27(5):1361-6.
    PMID: 27391504 DOI: 10.1097/SCS.0000000000002792
    The aim of this study was to describe the clinical features and expression of bcl-2, cyclin D1, p53, and proliferating cell nuclear antigen (PCNA) antibodies in syndromic (nevoid basal cell carcinoma syndrome [NBCCS]) and nonsyndromic patients diagnosed with keratocystic odontogenic tumor (KCOT).

    METHODS: This descriptive study comprised 5 patients of KCOT associated with NBCCS and 8 patients of nonsyndromic type treated in the Department of Oral Maxillofacial Surgery, Universiti Kebangsaan Malaysia Medical Centre between years 1998 and 2011. The clinical features (site, size, treatment, and recurrence), demographic characteristics, and immunohistochemistry results using antibodies of bcl-2, cyclin D1, p53, and PCNA were examined. The association of the antibody expression and the type of KCOT was analyzed using Fisher exact test.

    RESULTS: Altogether there were 13 patients, 5 with syndromic KCOT (1 patient met 3 major criteria of NBCCS) and 8 with sporadic KCOT. The age range for syndromic KCT was 11 to 21 years (mean 16.00 years, SD 4.36) and 10 to 54 years (median 24.50 years, interquartile range 19.00) for the nonsyndromic KCOT. Tumor recurrence occurred in 3 patients (7.7%); 1 patient from the syndromic and 2 patients from the nonsyndromic. The most positive expression was observed in PCNA for both the syndromic and nonsyndromic samples and the least positive expression involved the p53.

    CONCLUSION: PCNA, bcl-2 protein, and cyclin D1 expressions could be useful in evaluating the proliferative activity of the tumor and the aggressiveness of the clinical presentation; however, the authors would propose for larger sample size research for more definitive results.

  17. Nazimi AJ, Khoo SC, Nabil S, Nordin R, Lan TH, Rajandram RK, et al.
    J Craniofac Surg, 2019 Oct;30(7):2159-2162.
    PMID: 31232997 DOI: 10.1097/SCS.0000000000005667
    Orbital fractures pose specific challenge in its surgical management. One of the greatest challenges is to obtain satisfactory reconstruction by correct positioning of orbital implant. Intraoperative computed tomography (CT) scan may facilitate this procedure. The aim of this study was to describe the early use of intraoperative CT in orbital fractures repair in our center. The authors assessed the revision types and rates that have occurred with this technique. With the use of pre-surgical planning, optical intraoperative navigation, and intraoperative CT, the impact of intraoperative CT on the management of 5 cases involving a total number of 14 orbital wall fractures were described. There were 6 pure orbital blowout wall fractures reconstructed, involving both medial and inferior wall of the orbit fracturing the transition zone and 8 impure orbital wall fractures in orbitozygomaticomaxillary complex fracture. 4 patients underwent primary and 1 had delayed orbital reconstruction. Intraoperative CT resulted in intraoperative orbital implant revision, following final navigation planning position, in 40% (2/5) of patients or 14% (2/14) of the fractures. In revised cases, both implant repositioning was conducted at posterior ledge of orbit. Intraoperative CT confirmed true to original reconstruction of medial wall, inferior wall and transition zone of the orbit. Two selected cases were illustrated. In conclusion, intraoperative CT allows real-time assessment of fracture reduction and immediate orbital implant revision, especially at posterior ledge. As a result, no postoperative imaging was indicated in any of the patients. Long-term follow-ups for orbital fracture patients managed with intraoperative CT is suggested.
  18. Gharghan SK, Nordin R, Ismail M
    Sensors (Basel), 2014;14(8):15573-92.
    PMID: 25153141 DOI: 10.3390/s140815573
    In a wireless sensor network (WSN), saving power is a vital requirement. In this paper, a simple point-to-point bike WSN was considered. The data of bike parameters, speed and cadence, were monitored and transmitted via a wireless communication based on the ZigBee protocol. Since the bike parameters are monitored and transmitted on every bike wheel rotation, this means the sensor node does not sleep for a long time, causing power consumption to rise. Therefore, a newly proposed algorithm, known as the Redundancy and Converged Data (RCD) algorithm, was implemented for this application to put the sensor node into sleep mode while maintaining the performance measurements. This is achieved by minimizing the data packets transmitted as much as possible and fusing the data of speed and cadence by utilizing the correlation measurements between them to minimize the number of sensor nodes in the network to one node, which results in reduced power consumption, cost, and size, in addition to simpler hardware implementation. Execution of the proposed RCD algorithm shows that this approach can reduce the current consumption to 1.69 mA, and save 95% of the sensor node energy. Also, the comparison results with different wireless standard technologies demonstrate minimal current consumption in the sensor node.
  19. Gharghan SK, Nordin R, Ismail M
    Sensors (Basel), 2015;15(5):11741-68.
    PMID: 26007728 DOI: 10.3390/s150511741
    In this paper, we propose an energy-efficient transmission technique known as the sleep/wake algorithm for a bicycle torque sensor node. This paper aims to highlight the trade-off between energy efficiency and the communication range between the cyclist and coach. Two experiments were conducted. The first experiment utilised the Zigbee protocol (XBee S2), and the second experiment used the Advanced and Adaptive Network Technology (ANT) protocol based on the Nordic nRF24L01 radio transceiver chip. The current consumption of ANT was measured, simulated and compared with a torque sensor node that uses the XBee S2 protocol. In addition, an analytical model was derived to correlate the sensor node average current consumption with a crank arm cadence. The sensor node achieved 98% power savings for ANT relative to ZigBee when they were compared alone, and the power savings amounted to 30% when all components of the sensor node are considered. The achievable communication range was 65 and 50 m for ZigBee and ANT, respectively, during measurement on an outdoor cycling track (i.e., velodrome). The conclusions indicate that the ANT protocol is more suitable for use in a torque sensor node when power consumption is a crucial demand, whereas the ZigBee protocol is more convenient in ensuring data communication between cyclist and coach.
  20. Al-Mqdashi A, Sali A, Noordin NK, Hashim SJ, Nordin R
    Sensors (Basel), 2018 Dec 10;18(12).
    PMID: 30544684 DOI: 10.3390/s18124360
    Channel rendezvous is an initial and important process for establishing communications between secondary users (SUs) in distributed cognitive radio networks. Due to the drawbacks of the common control channel (CCC) based rendezvous approach, channel hopping (CH) has attracted a lot of research interests for achieving blind rendezvous. To ensure rendezvous within a finite time, most of the existing CH-based rendezvous schemes generate their CH sequences based on the whole global channel set in the network. However, due to the spatial and temporal variations in channel availabilities as well as the limitation of SUs sensing capabilities, the local available channel set (ACS) for each SU is usually a small subset of the global set. Therefore, following these global-based generated CH sequences can result in extensively long time-to-rendezvous (TTR) especially when the number of unavailable channels is large. In this paper, we propose two matrix-based CH rendezvous schemes in which the CH sequences are generated based on the ACSs only. We prove the guaranteed and full diversity rendezvous of the proposed schemes by deriving the theoretical upper bounds of their maximum TTRs. Furthermore, extensive simulation comparisons with other existing works are conducted which illustrate the superior performance of our schemes in terms of the TTR metrics.
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