• Title/Summary/Keyword: Randomized

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A Double-Hybrid Spread-Spectrum Technique for EMI Mitigation in DC-DC Switching Regulators

  • Dousoky, Gamal M.;Shoyama, Masahito;Ninomiya, Tamotsu
    • Journal of Power Electronics
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    • v.10 no.4
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    • pp.342-350
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    • 2010
  • Randomizing the switching frequency (RSF) to reduce the electromagnetic interference (EMI) of switching power converters is a well-known technique that has been previously discussed. The randomized pulse position (RPP) technique, in which the switching frequency is kept fixed while the pulse position (the delay from the starting of the switching cycle to the turn-on instant within the cycle) is randomized, has been previously addressed in the literature for the same purpose. This paper presents a double-hybrid technique (DHB) for EMI reduction in dc-dc switching regulators. The proposed technique employed both the RSF and the RPP techniques. To effectively spread the conducted-noise frequency spectrum and at the same time attain a satisfactory output voltage quality, two parameters (switching frequency and pulse position) were randomized, and a third parameter (the duty ratio) was controlled by a digital compensator. Implementation was achieved using field programmable gate array (FPGA) technology, which is increasingly being adopted in industrial electronic applications. To evaluate the contribution of the proposed DHB technique, investigations were carried out for each basic PWM, RPP, RSF, and DHB technique. Then a comparison was made of the performances achieved. The experimentally investigated features include the effect of each technique on the common-mode, differential-mode, and total conducted-noise characteristics, and their influence on the converter’s output ripple voltage.

A Review of Recent Clinical Studies of Herbal Medicine Treatment for Children's Stomatitis : Focusing on Randomized Controlled Trials in Traditional Chinese Medicine (소아 구내염의 한약치료에 대한 임상연구 동향: 중의학 무작위대조군 임상시험을 중심으로)

  • Heo, Yu Jin;Lee, Shin Hee;Cho, Yun Soo
    • The Journal of Pediatrics of Korean Medicine
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    • v.35 no.4
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    • pp.125-140
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    • 2021
  • Objectives This study aims to find out the recent trend of the herbal medicine treatment in children's stomatitis in China, and propose better methods to treat children's stomatitis in Korea. Methods The randomized controlled trials (RCT) relevant to 'Herbal medicine treatment on children's stomatitis' were searched using China Academic Journal (CAJ). The search method we used included search formula, (SU = '口內炎' + '口腔炎' + 'stomatitis') and (SU = '儿童' + '小儿' + 'children' + 'child') from 2000 to September 2021. Results A total of 9 RCTs were selected and analyzed. All reports showed that oral administration of herbal medicine were effective and improved clinical symptoms. The most-used herbal medicine category was Heat-clearing medicine (淸熱藥). Conclusions The literatures from China have shown that herbal medicine improves children's stomatitis. These outcomes may be helpful for the treatment of children's stomatitis in Korea. However, further studies are needed to develop treatment guidelines for children's stomatitis.

What Should Thoracic Surgeons Consider during Surgery for Ground-Glass Nodules?: Lymph Node Dissection

  • Kim, Hong Kwan
    • Journal of Chest Surgery
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    • v.54 no.5
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    • pp.342-347
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    • 2021
  • Thoracic surgeons need to be aware of several important points regarding intraoperative lymph node dissection during surgery for non-small cell lung cancer with ground-glass opacities. The first point relates to the need for lymph node dissection during sublobar resection. Since even patients undergoing sublobar resection may benefit from lymph node dissection, it should be selectively performed according to adequate indications, which require further study. Second, there seems to be no difference in postoperative morbidity between systematic sampling and systematic dissection, but the survival benefit from systematic dissection remains unclear. The results of randomized controlled trials on this topic are conflicting, and their evidence is jeopardized by a high risk of bias in terms of the study design. Therefore, further randomized controlled trials with a sound design should investigate this issue. Third, more favorable survival outcomes tend to be positively associated with the number of examined lymph nodes. Minimum requirements for the number of examined lymph nodes in non-small cell lung cancer should be defined in the future. Finally, lobe-specific lymph node dissection does not have a negative prognostic impact. It should not be routinely performed, but it can be recommended in selected patients with smaller, less invasive tumors. Results from an ongoing randomized controlled trial on this topic should be awaited.

Application of Traditional East Asian Herbal Medicine for Atrophic Vaginitis: A Systematic Review of Randomized Controlled Trials (위축성 질염에 대한 한약 투약의 효과 : 체계적 문헌 고찰)

  • Park, Eo-Jin;Jo, Hee-Geun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.32 no.3
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    • pp.227-244
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    • 2019
  • Objectives: To evaluate the effectiveness and safety of application of Traditional East Asian Herbal Medicine (TEAM) in the treatment of Atrophic Vaginitis (AV). Methods: Randomized Controlled Trials (RCTs) were obtained from PubMed, Cochrane Library, Embase, CNKI, RISS, NDSL, and KISS. The risk of bias was assessed by using Cochrane's risk of bias tool, and RevMan 5.3 software was used. Results: 26 RCTs with 3,162 patients were identified and reviewed. Among them, 21 RCTs observe the effect of integrated traditional Chinese and Western medicine. 23 RCTs reported treatment groups was statistically effective than control groups in the study. Also, the recurrence rate was estimated in 10 RCTs and was lower than control groups. 12 studies observed adverse events (AEs) and severe AEs were not reported. Conclusions: This review suggested that TEAM was safe and effective in the treatment of AV. TEAM may also decrease the recurrence rate. However, this could not be proven conclusively. To ensure evidence-based clinical practice, well-designed trials with larger sample sizes are needed.

An Ensemble Cascading Extremely Randomized Trees Framework for Short-Term Traffic Flow Prediction

  • Zhang, Fan;Bai, Jing;Li, Xiaoyu;Pei, Changxing;Havyarimana, Vincent
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.4
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    • pp.1975-1988
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    • 2019
  • Short-term traffic flow prediction plays an important role in intelligent transportation systems (ITS) in areas such as transportation management, traffic control and guidance. For short-term traffic flow regression predictions, the main challenge stems from the non-stationary property of traffic flow data. In this paper, we design an ensemble cascading prediction framework based on extremely randomized trees (extra-trees) using a boosting technique called EET to predict the short-term traffic flow under non-stationary environments. Extra-trees is a tree-based ensemble method. It essentially consists of strongly randomizing both the attribute and cut-point choices while splitting a tree node. This mechanism reduces the variance of the model and is, therefore, more suitable for traffic flow regression prediction in non-stationary environments. Moreover, the extra-trees algorithm uses boosting ensemble technique averaging to improve the predictive accuracy and control overfitting. To the best of our knowledge, this is the first time that extra-trees have been used as fundamental building blocks in boosting committee machines. The proposed approach involves predicting 5 min in advance using real-time traffic flow data in the context of inherently considering temporal and spatial correlations. Experiments demonstrate that the proposed method achieves higher accuracy and lower variance and computational complexity when compared to the existing methods.

A Review of Randomized Controlled Trials on the Treatment Effects of Herbal Medicine for Hyperemesis Gravidarum (임신오조의 한약 치료 효과에 대한 무작위 대조군 임상 연구 고찰)

  • Lee, Ji-Won;Ahn, Soo-Yeon;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.34 no.4
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    • pp.62-77
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    • 2021
  • Objectives: This study aimed to anaylze randomized controlled trials on the effectiveness of herbal medicine for hyperemesis gravidarum. Methods: We searched the randomized controlled trials that intervented oral herbal medicine treatment on hyperemesis gravidarum retrieved using seven domestic and foreign databases. Literature search was conducted on April 19, 2021. Results: 185 studies were searched, and 7 were finally selected based on inclusion and exclusion criteria. All subjects were treated with western symptomatic treatment and in treatment group, additional oral herbal medicine was administered. Although the evaluation index was different for each study, all the indexes in the treatment group were significantly improved compared to the control group. Conclusions: Herbal medicine treatment for hyperemesis gravidarum showed significant effectiveness compared to western symptomatic treatment. In the future, additional studies are needed to evaluate the safety of herbal medicine treatment.

A Review of Randomized Controlled Trials of Pes Anserinus Tendinitis/Bursitis Syndrome in the China National Knowledge Infrastructure Database

  • Choi, Hyo Jung;Back, Hye Kyung;Kim, Young-Jun;Oh, Da Yoon;Park, Cheol Woo;Namgoong, Jin
    • Journal of Acupuncture Research
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    • v.38 no.4
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    • pp.284-292
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    • 2021
  • The purpose of this study was to review randomized controlled trials (RCTs) of pes anserinus tendinitis or bursitis (PATB) syndrome in the China National Knowledge Infrastructure database to investigate the efficacy of traditional Chinese medicine treatment for PATB syndrome. There were 20 RCTs published from 2001 to 2021 which were selected for analysis by publication year, number of samples, evaluation criteria, treatment duration, and treatment method. Out of the 142 retrieved RCTs, 20 were relevant to this review, and had performed Chinese medicine treatments including acupuncture (the most common treatment typically using acupoints SP10, ST35, SP9, and LR8), manipulation (typically using acupoints ST35, SP10, and SP9), and external application therapy (typically herbal medicine) in the treatment of PATB syndrome. Chinese medicine treatments were used widely in the treatment of PATB syndrome. We hope in the future, this review may initiate the development of treatments for PATB syndrome using Korean medicine.

Effects of Vibration Rolling on Ankle Range of Motion and Ankle Muscle Stiffness in Stroke Patients: A Randomized Crossover Study

  • Park, Seju;Jeong, Hojin;Kim, Byeonggeun
    • Journal of International Academy of Physical Therapy Research
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    • v.12 no.1
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    • pp.2272-2278
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    • 2021
  • Background: Vibration stimulation has emerged as a treatment tool to help reduce spasticity during physical therapy. Spasticity includes problems of reduced range of motion (ROM) and stiffness. However, the benefits of vibration rolling (VR) on interventions for stroke patients are unclear. Objectives: This study aimed to investigate the effect of VR intervention on the ankle ROM and ankle stiffness in stroke patients. Design: A randomized crossover study. Methods: Seven stroke patients completed two test sessions (one VR and one non-VR [NVR]) in a randomized order, with 48 hours of rest between each session. Participants completed intervention and its measurements on the same day. The measurements included ankle dorsiflexion and plantarflexion ROM and stiffness of ankle muscles, including the tibialis anterior, medial, and lateral gastrocnemius muscle. Results: After VR, ankle dorsiflexion ROM, lateral gastrocnemius stiffness, and medial gastrocnemius stiffness improved significantly (all P<.05). After NVR, only the lateral gastrocnemius stiffness improved significantly (P<.05). Furthermore, in the cases of changed values for ankle dorsiflexion ROM and lateral gastrocnemius stiffness were compared within groups, VR showed a more significant difference than NVR (P<.05) Conclusion: VR improved ankle ROM and muscle stiffness. Therefore, we suggest that practitioners need to consider VR as an intervention to improve dorsiflexion ROM and gastrocnemius stiffness in stroke patients.

Relationship between Postural Balance Training and Fall Risks for Elderly: a Systematic Review of Randomized Controlled Trials

  • Kim, Heesuk;Hwang, Sujin
    • Physical Therapy Rehabilitation Science
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    • v.10 no.2
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    • pp.185-196
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    • 2021
  • Objective: Falling is one of main accident to facilitate the physical injuries in order adults. The purpose of the systematic review was to determine the effects of postural balance training whether the recovery of falls in elderly with normal physical function or not throughout summing the selected studies quantitatively. Design: A systematic review Methods: MEDLINE and other four databases were searched up to April 20, 2021 and randomized controlled trials (RCTs) evaluating postural balance approaches on fall risks in elderly. The researched studies excluded the double studies, titles and abstract, and finally full-reported study. The selected RCTs studies were extracted characteristics of the studies and summary of results based on PICOS-SD (population, intervention, comparison, outcomes, and setting- study design) model to synthesize the papers qualitatively. Results: The review involved 22 RCT reports with 4,847 community older adults aged 65 years or over. Nineteen of the selected RCT studies reported dual or multimodal exercises show the beneficial effect for older adults compared to one-type treatment or no intervention. All of selected showed low risk in the selection, attrition, and reporting bias. However, detection bias showed low risk at 75% records of the involved RCTs and performance bias was low risk at only three records. Conclusions: The results of the systematic review propose that a standardized therapeutic approach and the intensity are needed for improving risk of falls in older adults.

A Review of Randomized Controlled Trials of Traditional Chinese Medicine Treatment for Coronavirus Disease 2019 Patients (Coronavirus Disease-2019 환자 치료에 대한 중의 RCT 연구 동향)

  • Park, Ju-heon;Yoon, Seong-hoon;Lee, In
    • The Journal of Internal Korean Medicine
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    • v.43 no.1
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    • pp.41-52
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    • 2022
  • Objectives: The purpose of this study is to investigate recent trends in randomized controlled trials (RCTs) on the treatment of Coronavirus disease 2019 (COVID-19) patients with traditional Chinese medicine (TCM) and analyze the results for the activation of COVID-19 Korean medicine research. Methods: We searched for RCTs published from December 2019 to October 2021 in the Chinese National Knowledge Infrastructure Database (CNKI). The investigation focused on the type of study, the purpose of the study, and the treatment methods. Results: A total of 8 RCTs were selected and analyzed from the 447 searched studies. All studies attempted to observe the effects of herbal medicine. Herbal medicine included granules, decoctions, and intravenous injections. The most frequently used herb type was drugs for clearing away heat and detoxification and releasing the exterior syndrome. In most studies, the effectiveness of TCM treatment of COVID-19 was significantly high. Conclusions: Although more quality studies are needed to support these results, TCM treatment for COVID-19 has been effective. Therefore, we hope that Korean medicine studies on infectious diseases will be actively conducted like TCM and contribute to national health.