• Journal of Oral Medicine and Pain
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• 제40권4호
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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.

• 한국인터넷방송통신학회논문지
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• 제14권1호
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• pp.85-91
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• 2014

본 논문은 16-QAM 신호 전송시 시분산 채널에서 발생되는 진폭과 위상 찌그러짐에 의한 부호간 간섭을 경감시키기 위한 적응 등화 알고리즘인 VSDA (Variable stepsize Square contour Decision directed Algorithm)의 성능에 관한 것이다. 기존 SCA 에서는 송신 신호의 2차 통계치인 Constellation Dependent Constant를 이용하여 수신 신호의 진폭과 위상을 보상하지만, VSDA에서는 constellation matching을 위한 distance adjusted approach 개념과 decision directed 비용 함수를 부가하여 수렴 성능을 더욱 개선시킨 것이다. 논문에서는 컴퓨터 시뮬레이션을 통하여 VSDA와 SCA의 등화 성능을 비교하였으며, 이를 위한 성능 지수로는 등화기 출력 신호 성상도, 잔류 isi양, 최대 찌그러짐 및 MSE를 사용하였다. 성능의 비교 결과 수렴 속도에서는 VSDA 알고리즘이 SCA보다 훨씬 개선되었지만, 모든 성능 지수는 유사함을 알 수 있었다.

• 한국전자파학회논문지
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• 제12권5호
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• pp.665-675
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• 2001

본 논문은 다중접속 간섭을 효과적으로 제거할 수 있는 기지국 어레이 안테나를 이용하여 전파음영 환경하에서 빔 형성 알고리즘과 전력 제어 오차에 따른 DS/CDMA 셀룰라 시스템의 역방향 링크에 대한 성능을 분석한다. 블로킹(blocking) 확률을 어레이 파라미터와 E$_{b}$/N$_{o}$ 및 간섭 통계를 이용하여 유도하고 특정한 블록킹 확률에 일치하는 시스템 용량을 계산하다. 1%의 블록킹 확률을 가정하였을 경우, 동방성 안테나 1개를 사용하는 경우보다는 12개의 어레이 안테나를 이용한 MCGM 알고리즘을 사용하였을 경우에 약 32배의 시스템 용량이 증가함을 보인다.

• 인터넷정보학회논문지
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• 제19권1호
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• pp.11-17
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• 2018

본 논문에서는 회사 또는 백화점 등과 같은 고층 건물에 다수의 펨토셀 기지국들(Femtocell base stations, fBSs)이 밀집되어 배치되는 기업형 펨토셀 네트워크(Enterprise femtocell network, EFN) 환경에서 부분 주파수 재사용 (Fractional frequency reuse, FFR) 자원할당 방법을 이용하여 하향링크에 대한 시스템 성능을 분석한다. 이를 위해, 먼저 매크로셀과 펨토셀 사이의 주파수 간섭을 완화시키는 Split reuse 주파수 할당 방법에 대해 소개하고, 이후 EFN의 fBS들에게 주파수 간섭 완화 및 주파수 효율을 극대화할 수 있는 FFR을 이용한 자원할당 방법을 제안한다. 마지막으로 시뮬레이션을 통해 제안하는 FFR 자원할당 방법의 시스템 성능을 분석하고, EFN 환경에서 주파수 재사용 계수(Frequency reuse factor: FRF)를 4로 사용하는 전형적인 FRF 4 방법보다 제안하는 FFR 자원할당 방법이 평균 fUE 용량, 전체 EFN 용량, 그리고 Outage probability 측면에서 우수한 성능임을 보인다.

• 한국인터넷방송통신학회논문지
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• 제13권4호
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• pp.67-73
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• 2013

본 논문은 16-QAM 신호 전송시 시분산 채널에서 발생되는 찌그러짐에 의한 부호간 간섭을 경감시키기 위한 적응 등화 알고리즘인 VSCA (Variable stepsize Square Contour Algorithm)의 성능에 관한 것이다. 기존의 SCA에서는 송신 신호의 2차 통계치를 이용한 Constellation Dependent Constant를 이용하여 부호간 간섭이 존재하는 수신 신호의 진폭과 위상을 보상하지만, VSCA에서는 constellation matching을 위한 distance adjusted approach 개념을 부가하여 적응 등화 성능을 더욱 개선시켰다. 논문에서는 VSCA의 개선된 성능을 SCA와 비교하였으며, 이를 위한 성능 지로로는 등화기 출력 신호 성상도, 잔류 isi양, 최대 찌그러짐 및 MSE를 사용하였다. 컴퓨터 시뮬레이션의 성능비교 결과 모든 지수에서 VSCA 알고리즘이 SCA보다 우월함을 확인할 수 있었다.

• 여성건강간호학회지
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• 제27권1호
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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.

• 재활간호학회지
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• 제3권1호
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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.

• 한국음향학회지
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• 제20권6호
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• pp.87-93
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• 2001

본 논문에서는 일반적인 코드분할 다중화 시스템을 위해 저자가 제안하였던 유사 역상관기를 변형하여 광대역 코드분할 다중화 시스템에 적합한 수신기를 설계하고, 백색 가우시안 채널 환경에서 성능을 분석하고 있다. 설계된 수신기에서는 판단변수에 포함되어 있는 다중사용자 간섭신호를 분석하여, 송신된 신호의 각 비트에 대응되는 상호상관행렬을 얻게 된다. 이 상호상관행렬을 역변환시킨 후, 기존의 수신기에서 얻어진 판단변수에 적용한다. 이렇게 해서 수신기의 성능을 향상시킬 수 있다. 제안된 수신기는 연속해서 3비트를 받은 후에 바로 검출과정을 수행할 수 있다는 잇점이 있다. 지연시간이나 반송파 위상 오차가 존재하는 상황에서 설계된 수신기의 성능변화를 백색 가우시안 채널에서의 여러 가지 시뮬레이션을 통해서 확인하였다. 그 결과 여기에서 제안한 수신기가 기존 수신기나, 병렬 간섭제거기에 비해 성능이 우수하다는 것을 알 수 있었다.

• Journal of Communications and Networks
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• 제11권2호
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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.

• ETRI Journal
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• 제29권2호
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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.