• Title/Summary/Keyword: interference statistics

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Sleep Quality of Patients with Temporomandibular Disorders: Relationship to Clinical and Psychological Characteristics

  • Song, Kyung-Won;Kim, Mee-Eun
    • Journal of Oral Medicine and Pain
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    • v.40 no.4
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    • pp.155-162
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    • 2015
  • Purpose: The association between pain and sleep is described as a vicious cycle and psychological distress is well known as comorbid condition in the patients with pain and sleep problems. The aim of the study was to evaluate the prevalence of self-reported sleep disturbance and its relationship to clinical and psychological profiles in temporomandibular disorder (TMD) patients. Methods: The sample consisted of 123 TMD patients (90 women and 33 men), with a mean age of $39.9{\pm}15.4years$. Self-report measures of sleep quality, pain and psychological profile were conducted via the Pittsburgh Sleep Quality Index (PSQI), the Brief Pain Inventory and the Symptom Checklist-90-Revision at the initial visit. The primary diagnosis of TMD were categorized as TMD with internal derangement without pain, TMD with joint pain, TMD with muscle pain and TMD with joint-muscle combined pain. The chi-square test, independent t-test, oneway ANOVA and multiple linear regression analysis were used for statistics. Results: The patients was grouped as good sleepers (n=32, scores of 5 and lower) and poor sleepers (n=91, scores of 6 and higher) according to the recommended cutoff point of the global PSQI score (>5). TMD patients with pain showed poor sleep quality than TMD patients with internal derangement without pain. Poor sleepers had high pain interference and elevated psychological distress. Among them, pain interference and depression were significant predictors to sleep quality. Conclusions: The results suggest that sleep disturbance is a prevalent complaint in TMD patients, and sleep problems in TMD patients are associated with pain and psychological distress.

Performance Evaluation of VSDA Blind Equalization Algorithm for 16-QAM Signal (16-QAM 신호에 대한 VSDA 블라인드 등화 알고리즘의 성능 평가)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.85-91
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    • 2014
  • This paper relates with the VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference due to the distortion which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the conventional SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSDA, it is possible to the increasing the equalization performance by adding the concept of distance adjusted approach for constellation matching and the cost function of decision directed. We compare the performance of VSDA and SCA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSDA algorithm has better than the SCA in convergence speed, but it gives nearly same equalization performance in other index.

The Performance Analysis of a DS/CDMA Cellular System considering a Base Station Array Antenna and Imperfect Power Control (기지국 어레이 안테나와 불완전 전력 제어를 고려한 DS/CDMA 셀룰라 시스템의 성능 분석)

  • kim, Hyoung-Chae;Kim, Hang-Rae;Kim, Nam;Han, Tae-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.5
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    • pp.665-675
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    • 2001
  • In this paper, the reverse link performance of a imperfect power controlled DS/CDMA cellular system that uses a base station array antenna which can effectively remove the multiple access interference is analyzed considering both beam forming algorithm and power control error in shadowing. The blocking probability of the DS/CDMA cellular system based on array parameters, $E_b/N_o$ and statistics of interference is derived, and then the system capacity corresponding to a certain blocking probability is calculated. On the assumption that the blocking probability is set 1%, the system capacity using MCGM algorithm with 12 antenna arrays is more increased maximum 32 times than that using a omni-directional antenna and about 2 times than that using MMSE algorithm, respectively.

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Performance Analysis of Fractional Frequency Reuse Scheme for Enterprise Femtocell Networks (기업형 펨토셀 네트워크에서 부분 주파수 재사용 방법의 성능분석)

  • Kim, Se-Jin
    • Journal of Internet Computing and Services
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    • v.19 no.1
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    • pp.11-17
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    • 2018
  • In this paper, we propose a novel frequency reuse method using the fractional frequency reuse (FFR) for enterprise femtocell networks (EFNs) in which a lot of femtocell base stations (fBSs) are deployed in a buinding, e.g., business companies, department stores, etc, and evaluate the system performance for the downlink of EFNs. First, we introduce the concept of the split reuse method to allocate the frequency bandwidth with considering the interference between the macrocell and femtocell. Then, we propose the resource allocation with the FFR for fBSs of EFNs to reduce the interference and increase the system capacity. Through simulations, we show that the proposed FFR method outperforms a traditional resource allocation method with frequency reuse factor 4 in terms of the mean fUE capacity, total EFN capacity, and outage probability.

Performance of VSCA Adaptive Equalization Algorithm for 16-QAM Signal (16-QAM 신호에 대한 VSCA 적응 등화 알고리즘의 성능)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.4
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    • pp.67-73
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    • 2013
  • This paper relates with the performance of VSCA adaptive equalization algorithm that is used for the minimization of the intersymbol interference due to the distortion which occurs in the time dispersive channel for the transmission of 16-QAM signal. In the conventional SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSCA, it is possible to the increase the equalization performance by adding the concept of distance adjusted approach for constellation matching. We compare the performance of VSCA and SCA algorithm by computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used for perfomance comparison. It was confirmed that, the VSCA algorithm has better than the SCA in every performance index by computer simulation.

What influences aromatase inhibitor continuation intention among breast cancer survivors?

  • Seo, Young Kyung;Park, Jeongok;Park, Jin-Hee;Kim, Sue
    • Women's Health Nursing
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    • v.27 no.1
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    • pp.49-57
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    • 2021
  • Purpose: Aromatase inhibitors (AIs) are widely prescribed for postmenopausal women with breast cancer and are known to cause musculoskeletal pain. This study aimed to identify factors associated with AI continuation intention among breast cancer survivors (BCS). Methods: A cross-sectional survey was conducted on 123 BCS (stages I-III), who had been taking AIs for at least 6 weeks. Participants were recruited from a cancer center in Goyang, Korea, from September to November 2019. Descriptive statistics, Welch analysis of variance, Pearson correlation coefficients, and simple linear regression were used for the analysis. Results: Beliefs about endocrine therapy was a significant predictor of AI continuation intention (β=.66, p<.001). The majority of participants (87.0%) reported experiencing musculoskeletal pain since taking AIs and the score for the worst pain severity within 24 hours was 5.08±2.80 out of 10. Musculoskeletal pain, however, was not associated with AI continuation intention. Fear of cancer recurrence (FCR) was clinically significant (≥13) for 74.0% of the respondents (mean, 17.62±7.14). Musculoskeletal pain severity and pain interference were significantly associated with FCR (r=.21, p<.05; r=.35, p<.01, respectively). Pain interference was significantly associated with beliefs about endocrine therapy (r=-.18, p<.05). Conclusion: AI continuation intention can be modified by reinforcing patients' beliefs about endocrine therapy. Musculoskeletal pain may have a negative effect on beliefs about endocrine therapy and increase FCR among BCS. Thus, awareness of musculoskeletal pain during AI therapy should be raised and further research is required to develop multidisciplinary pain management strategies and clinical guidelines to reinforce beliefs about endocrine therapy.

A Study on Patients' Concerns about Management of Cancer Pain and Related Factors (종양통증관리를 방해하는 환자의 염려와 관련요인 연구)

  • Kim, Hong-Soo;Suh, Moon-Ja
    • The Korean Journal of Rehabilitation Nursing
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    • v.3 no.1
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    • pp.43-58
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    • 2000
  • Pain management is a major issue in caring of cancer patients. Patients' concerns for reporting pain and taking analgesics are patient-related barriers to the management of cancer pain. Since such study has not been done at all in Korea, it is clearly needed to study on these problems. The purpose of this study is to attain basic data in order to improve cancer pain management in Korea. This is done by: 1) examining the extent of patients' concerns that might be barriers to the optimal pain management, and the extent of related factors (pain management hesitancy, adequacy of using analgesics, pain severity and pain interference); 2) identifying the relationship between patients' concerns and the related factors. The data has been collected from 180 cancer patients who were hospitalized in medical wards of one university hospital in Seoul, Korea during the period from November 1, 1997 to February 28, 1998. The data has been collected through interviews with (1) Barriers Questionnaire - Korean Version (BQ-K); (2) Hesitancy Experience Questionnaires (HQ); (3) Pain Management Index (PMI); (4) Brief Pain Inventory (BPI); and (5) Demographic Data. The data were analyzed by descriptive statistics and by t-test, One-way ANOVA, Pearson correlation using SPSSWIN program. The Results are as following: 1) The mean scores of Pain Management Concerns (PMC) by BQ-K were toward the moderate with a little high points(2.59). Most of the patients (99.4%) had some extent of concerns (over lout of maximum 5 points). Among the eight subscales of BQ-K, the Pain Management Concerns (PMC) about 'Fear of tolerance' was the highest (3.80) and 'Worry about side effects' was the least (1.40). 2) The extent of Pain Management Hesitancy (PMH) by HQ of wnom had pain on the day of the interview was a little higher than moderate score(5.53 out of maximum 10 points). 6.7% of the patients with experiencing pain used less adequate analgesics for the severity of pain than they were expected. 27.8% of them never used any analgesics at all. The mean score of pain severity by BPI was 16.59 (maximum: 40), and that of the interference with daily life by BPI was 32.03 (maximum: 70). 3) The patients who were older, less educated, and in low socio-economic status were likely to have more concerns. Pain Management Concerns (PMC) was positively correlated with Pain Management Hesitancy (PMH) (r=.75), pain severity (r=.44) and pain interference (r=.50). Those who were not using adequate analgesics had higher Pain Management Concerns (PMC) than did those who were using adequate analgesics (t=-5.42). The patients who had more Pain Management Concerns (PMC) tended to hesitate more to report pain and to use analgesics. They used more inadequate analgesics for the severity of pain and also had experienced more pain severity and interference with daily life. In conclusion, the patients' concerns for reporting pain and for using analgesics are major patient-related barriers to cancer pain management in Korea. The patients' concerns were correlated significantly with the level of the hesitancy experience, inadequate use of analgesics, the pain severity and the interference with daily life. Considering this, an educational program for cancer patients under the treatment with analgesics should be developed in order to solve these problems.

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Performance Analysis of a Receiver for WCDMA Systems (광대역 코드분할 다중화 시스템 수신기의 성능 분석)

  • 박중후
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.6
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    • pp.87-93
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    • 2001
  • As a new type of a linear decorrelating receiver, the Pseudo-Decorrelator was presented for asynchronous code division multiple access systems by the author. In this paper, the concept of the Pseudo-Decorrelator is extended to derive a receiver for WCDMA uplink systems over an additive white Gaussian noise channel. Starting with the analysis of the multiple access components of the decision statistics, a non-square cross-correlation matrix for each bit is obtained. This cross-correlation matrix is then inverted, and the inverted matrix is applied to the decision statistics obtained from a conventional receiver. In this receiver, the detection process can be started after the first three consecutive bits are received. Simulation results are presented for K-user systems over an additive white Gaussian noise channel under the circumstances in which synchronization errors, including time delay errors and carrier phase errors exist. It is shown that the proposed receiver performs better than a conventional receiver and parallel interference canceller.

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Large-Scale Joint Rate and Power Allocation Algorithm Combined with Admission Control in Cognitive Radio Networks

  • Shin, Woo-Jin;Park, Kyoung-Youp;Kim, Dong-In;Kwon, Jang-Woo
    • Journal of Communications and Networks
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    • v.11 no.2
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    • pp.157-165
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    • 2009
  • In this paper, we investigate a dynamic spectrum sharing problem for the centralized uplink cognitive radio networks using orthogonal frequency division multiple access. We formulate a large-scale joint rate and power allocation as an optimization problem under quality of service constraint for secondary users and interference constraint for primary users. We also suggest admission control to nd a feasible solution to the optimization problem. To implement the resource allocation on a large-scale, we introduce a notion of using the conservative factors $\alpha$ and $\beta$ depending on the outage and violation probabilities. Since estimating instantaneous channel gains is costly and requires high complexity, the proposed algorithm pursues a practical and implementation-friendly resource allocation. Simulation results demonstrate that the large-scale joint rate and power allocation incurs a slight loss in system throughput over the instantaneous one, but it achieves lower complexity with less sensitivity to variations in shadowing statistics.

Calculation of Spectral Efficiency for Estimating Spectrum Requirements of IMT-Advanced in Korean Mobile Communication Environments

  • Chung, Woo-Ghee;Lim, Eun-Taek;Yook, Jong-Gwan;Park, Han-Kyu
    • ETRI Journal
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    • v.29 no.2
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    • pp.153-161
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    • 2007
  • In this paper, we analyze the algorithm of the methodology developed by ITU for the calculation of spectrum requirements of IMT-Advanced. We propose an approach to estimate user density using traffic statistics, and to estimate spectrum efficiencies using carrier-to-interference ratio distribution and capacity theory as well as experimental data under Korean mobile communication environments. We calculate the IMT-Advanced spectrum requirements based on the user density and spectral efficiencies acquired from the new method. In the case of spectral efficiency using higher modulation and coding schemes, the spectrum requirement of IMT-Advanced is approximately 2700 MHz. When applying a $2{\times}2$ multiple-input multiple-output (MIMO) antenna system, it is approximately 1500 MHz; when applying a $4{\times}4$ MIMO antenna system, it is approximately 1050 MHz. Considering that the development of new technology will increase spectrum efficiency in the future, the spectrum requirement of IMT-Advanced in the Korean mobile communication environment is expected to be approximately 1 GHz bandwidth.

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