• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.52-57
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• 2012

We propose a weighted time-reversal prefilter for indoor wireless communication systems. In the indoor wireless communication environments, the bit error rate (BER) performance is significantly degraded by the delay spread. The conventional schemes have complex receivers to recover deterioration of the BER. The proposed time-reversal prefilter simplifies the structure of receivers, minimizes the inter-symbol interference (ISI) and maintains the peak power level of the received signal. The simulation results show that the weighted time-reversal prefilter improves the BER performance in comparison with the conventional time-reversal prefilter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.917-920
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• 2006

In mobile environments, their is more than one propagation path between each transceiver and Receiver have two or more delayed multipath signals. Delayed multipath signals can cause ISI and Receiver needs a adaptive algorithm to estimate a channel periodically. Also adaptive antenna using adaptive algorithm provide a significant increase in capacity, performance and coverage. This paper describes various LMS algorithm and evaluate the performance of array antenna Base station by using LMS algorithm in the presence of multipath signals and multiple users. As a result of simulation, Adaptive array antenna systems are able to adjust their antenna pattern to select desired signals, and reduce interference.

• Journal of Acupuncture Research
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• v.29 no.5
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• pp.109-118
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• 2012

Objectives : The aim of this study was to evaluate the effectiveness and safety of acupuncture for chronic fatigue syndrome and idiopathic chronic fatigue. Methods : A randomized, controlled pilot trial was conducted. Twenty-four participants were randomized into one of the two groups: an acupuncture group(n=12) and wait-list group(n=12). The treatment group received 12 sessions of acupuncture over 4 weeks. Eight points($GV_{20}$; bilateral GB20, $BL_{11}$, $BL_{13}$, $BL_{15}$, $BL_{18}$, $BL_{20}$, and $BL_{23}$) were selected for needling. The control group did not receive acupuncture treatment during study period and follow-up were done in the $5^{th}$ and $9^{th}$ weeks after randomization in both groups. The primary outcome was fatigue severity scale(FSS) and the secondary outcomes included a short form of stress response inventory(SRI-short form), beck depression inventory(BDI), and insomnia severity index(ISI). Safety was assessed at every visit. Results : There were statistically significant differences in the between group values of FSS at $5^{th}$ weeks after randomization(p=0.0002), SRI-short form, BDI, and ISI at $5^{th}$, $9^{th}$ weeks after randomization(p<0.01). There were no adverse events. Conclusions : The results suggest that acupuncture is associated with benefits on the short-term outcomes in chronic fatigue syndrome and idiopathic chronic fatigue.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.58-64
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• 2012

We propose a double time reversal (TR) prefilter for high data rate and minimum interference in multi-user indoor communication system. A conventional TR prefilter degrades bit error rate (BER) performance significantly because it cannot remove the interference perfectly. As the symbol duration is close, the BER performance is deteriorated. Since the proposed scheme aims to minimize interference, high data rate is realized without the performance degradation and the complexity of receiver is reduced through an additional prefilter design. Simulation results show that the performance of the proposed scheme is improved as the number of users is increased or the data rate becomes high.

• Korean Journal of Occupational Health Nursing
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• v.33 no.2
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• pp.47-54
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• 2024

Purpose: This study aims to identify the level of subjective noise perception among School Meal Facility Workers and analyze the relationship between subjective noise perception and insomnia, as well as the factors affecting insomnia. Methods: School meal facility workers were surveyed from November 1 to December 31, 2021, and 717 people were selected as participants for the study. Using SPSS/WIN 25.0, t-test, x² test, and multiple logistic regression analysis were conducted. The Korean Insomnia Severity Index (ISI-K) was used to evaluate insomnia. Results: The variables that showed significant differences in insomnia in general characteristics, health-related characteristics, subjective health perception, and subjective noise perception of the study participants were mental disorders such as subjective health perception, work stress, depression, etc., gastrointestinal disorders, and subjective noise perception, among which subjective health perception, mental disorders such as depression, and subjective noise perception were analyzed as factors influencing insomnia. Conclusion: To improve the quality of insomnia and sleep among school meal facility workers, there is a need to improve healthcare, emotional management, and noisy work environments.

• Journal of Oriental Neuropsychiatry
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• v.31 no.2
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• pp.63-76
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• 2020

Objectives: The purpose of this study was to verify the clinical effects of herbal medicines on patients with depressive disorder. Methods: A prospective observational study on patients with depressive disorder was conducted. The patients were treated with herbal medicines for eight weeks. The Korean Hamilton Depression Rating Scale (K-HDRS) was evaluated as the primary outcome and the Korean Beck's Depression Inventory (K-BDI), Instrument on Pattern Identification for Depression, Korean Symptom Checklist-95 (KSCL-95), Insomnia Severity Index (ISI), Korean State-Trait Anxiety Inventory (STAI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), EuroQol five-dimensional Questionnaire (EQ-5D), Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Heart Rate Variability (HRV) were measured as the secondary outcome. Adverse events were assessed for safety. Results: A total of 35 participants were observed for 12 weeks. The K-HDRS improved significantly in four, eight, and 12 weeks and the K-BDI showed significant differences in four, and eight weeks. There were no significant improvements in other evaluation scales. Gyejibongnyeong-hwan was the most frequently and continuously prescribed, showing significant improvements of K-HDRS after eight weeks of treatment. Conclusions: In our observational study, herbal medicine was effective for relieving the depression of patients with depressive disorder and Gyejibongnyeong-hwan showed the most significant effectiveness.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.469-475
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• 2014

BACKGROUND/OBJECTIVE: The goal of the present study was to investigate the effects of moderate caloric restriction on ${\beta}$-cell function and insulin sensitivity in middle-aged obese Korean women. SUBJECTS/METHODS: Fifty-seven obese pre-menopausal Korean women participated in a 12-week calorie restriction program. Data on total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), and fasting serum levels of glucose, insulin, C-peptide, blood pressure, leptin and anthropometrics were collected. A dietary intake assessment was based on three days of food recording. Additionally, ${\beta}$-cell function [homeostasis model assessment of ${\beta}$-cell (HOMA-${\beta}$), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose ($AUC_{ins/glu}$)] and insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR), Quantitative insulin-sensitivity check index (QUICKI) and Matsuda index (MI)] were recorded. RESULTS: When calories were reduced by an average of 422 kcal/day for 12 weeks, BMI (-2.7%), body fat mass (-10.2%), and waist circumference (-5%) all decreased significantly (P < 0.05). After calorie restriction, weight, body fat percentage, hip circumference, BP, TC, HDL-C, LDL-C, plasma glucose at fasting, insulin at fasting and 120 min, $AUC_{glu}$ and the insulin area under the curve all decreased significantly (all P < 0.05), while insulin sensitivity (HOMA-IR, QUICKI and Matsuda index) measured by OGTT improved significantly (P < 0.01). CONCLUSIONS: Moderate weight loss due to caloric restriction with reduction in insulin resistance improves glucose tolerance and insulin sensitivity in middle-aged obese women and thereby may help prevent the development of type 2 diabetes mellitus.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1A
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• pp.17-24
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• 2012

In this paper, we described a received signal model in terms of the starting point of FFT window and derive a post-detection SINR for the receiver with MMSE filter and the corresponding filter coefficients in order to mitigate the effects of interferences caused by time and frequency selective fading channels and time difference of arrival (TDoA) in OFDMA-based Mesh Networks. In addition, we proposed an MMSE Bidirectional Successive Detection (BSD) technique which can suppress the effects of interferences among multi-nodes without any redundant FFT operations. It was shown by simulation that the proposed interference suppression technique has not an error floor at higher average SNR than 30dB in terms of 64QAM uncoded BER contrary to the conventional techniques.

• Journal of Oral Medicine and Pain
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• v.45 no.2
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• pp.23-28
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• 2020

Purpose: Temporomadibular disorders (TMDs) can result in chronic pain, which is often associated with psychological and sleep disturbance. Increased levels of psychological and sleep impairments are often related with poor treatment outcomes. The purpose of the present study was to evaluate clinical features, psychological profiles and the prevalence of clinical insomnia in TMD patients with chronic pain and to suggest an effective treatment approach. Methods: A total of 200 TMD patients who had visited the Pusan National University Hospital dental clinic for treatment of their pain were recruited from June 2018 through December 2019. TMD patients were classified into an acute (n=100) and chronic (n=100) group and compared the clinical symptoms. The primary diagnosis of TMD were categorized as TMD with joint pain group (TMD_J), TMD with muscle pain group (TMD_M) and TMD with joint-muscle mixed pain group (TMD_JM). Self- report measures of sleep quality and psychological profiles were evaluated via the Insomnia Severity Index (ISI) and the Korean Stress Response Inventory (SRI). Independent t-tests, Mann-Whitney U-tests, and chisquared test were used for the statistical analysis. Results: Chronic TMD patients showed higher pain intensity, as well as higher prevalence of related symptoms (headache, musculoskeletal pain) and myogenous pain. They also had significantly higher scores in all SRI parameters and a higher percentage of clinical insomnia than acute TMD patients. Conclusions: Based on the above results, psychological profiles and sleep quality assessments are necessary to provide essential data that will allow for improved treatment of chronic TMD patients.

• The Journal of Korean Obstetrics and Gynecology
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• v.34 no.3
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• pp.157-174
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• 2021

Objectives: This case report aims to report the clinical effectiveness of the combination treatment of Korean medicine with Guibiondamtang-gamibang on Hwa-byung patients. Methods: Case 1 experienced stress at work and complained of chest discomfort, nausea, dizziness, insomnia. Case 2 experienced huge stress about money, and complained of palpitation, chest discomfort, dizziness and insomnia. They received combination treatment of Korean medicine during hospitalization. The treatment included Guibiondamtang-gamibang, acupuncture, moxibustion, pharmacoacupuncture, and fumigation. The effects were evaluated through Hwa-byung scale, instrument of oriental medical evaluation for Hwa-byung, insomnia severity index (ISI) and heart rate variability (HRV) test. Results: After the treatment, the clinical symptoms such as chest discomfort, palpitation, dizziness, nausea and insomnia were improved. Conclusions: This case report shows that the combination treatment of Korean medicine with Guibiondamtang-gamibang may be effective for treating Hwa-byung patients.