• Title/Summary/Keyword: systematic bias

Search Result 648, Processing Time 0.026 seconds

GPS/RTS data fusion to overcome signal deficiencies in certain bridge dynamic monitoring projects

  • Moschas, Fanis;Psimoulis, Panos A.;Stiros, Stathis C.
    • Smart Structures and Systems
    • /
    • v.12 no.3_4
    • /
    • pp.251-269
    • /
    • 2013
  • Measurement of deflections of certain bridges is usually hampered by corruption of the GPS signal by multipath associated with passing vehicles, resulting to unrealistically large apparent displacements. Field data from the Gorgopotamos train bridge in Greece and systematic experiments revealed that such bias is due to superimposition of two major effects, (i) changes in the geometry of satellites because of partial masking of certain satellites by the passing vehicles (this effect can be faced with solutions excluding satellites that get temporarily blocked by passing vehicles) and (ii) dynamic multipath caused from reflection of satellite signals on the passing trains, a high frequency multipath effect, different from the static multipath. Dynamic multipath seems to have rather irregular amplitude, depending on the geometry of measured satellites, but a typical pattern, mainly consisting of a baseline offset, wide base peaks correlating with the sequence of main reflective surfaces of the vehicles passing next to the antenna. In cases of limited corruption of GPS signal by dynamic multipath, corresponding to scale distortion of the short-period component of the GPS waveforms, we propose an algorithm which permits to reconstruct the waveform of bridge deflections using a weak fusion of GPS and RTS data, based on the complementary characteristics of the two instruments. By application of the proposed algorithm we managed to extract semi-static and dynamic displacements and oscillation frequencies of a historical railway bridge under train loading by using noisy GPS and RTS recordings. The combination of GPS and RTS is possible because these two sensors can be fully collocated and have complementary characteristics, with RTS and GPS focusing on the long- and short-period characteristics of the displacement, respectively.

Effect of aquatic exercise on gait in persons with chronic stroke: a meta-analysis study in Korea

  • Lee, Dong-Jin;Cho, Sung-Hyoun
    • Physical Therapy Rehabilitation Science
    • /
    • v.8 no.2
    • /
    • pp.112-123
    • /
    • 2019
  • Objective: Based on the results of previous studies, it is necessary to analyze gait and discuss and present the effects of aquatic exercise for chronic stroke. The purpose of this study was to present objective data on the effect of aquatic exercise on the gait of persons with stroke by performing a meta-analysis. Design: A systematic review and meta-analysis. Methods: We performed a meta-analysis of 23 studies that investigated the effects of aquatic exercise performed between 2006 and 2017. The studies were searched on the basis of the participants, intervention, comparison, outcomes standard. The quality of the research method was assessed using a tool that can assess the risks posed by each study design. A meta-analysis software program was used to calculate the mean effect size, effect size by intervention, and effect size by outcome. We also performed a meta-regression analysis and an analysis of publication bias. Results: The mean effect size of the patients' gait was 0.65 (p<0.05). The largest effect size by outcome was observed at the 6-m walk test, followed by the 6-minutes walk test, 10-m walk test, and the walking equipment test (p<0.05). The meta-regression analysis showed that the effect size increased with increased duration, number, and length of sessions. Conclusions: Aquatic exercise appears to show a moderate effect on the gait of chronic stroke survivors. Meta-analyses on the effects of aquatic exercise in other patient populations are needed. This study suggests standard criteria establishments for the effect of aquatic exercise on the walking ability of persons with chronic stroke.

Effect of Cardiopulmonary Physiotherapy on Patients With Percutaneous Coronary Intervention - Systematic Review and Meta-Analysis (경피적 관상동맥 중재술을 받은 환자를 대상으로 심장호흡물리치료에 대한 효과 - 체계적 고찰과 메타분석)

  • Kang, Na-yoon;Park, Beom-seok;Kim, Min-hee
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.14 no.1
    • /
    • pp.63-73
    • /
    • 2019
  • PURPOSE: This study examined the effects of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients with coronary artery disease who underwent percutaneous coronary intervention (PCI). METHODS: Electronic bibliographic databases of a regional information sharing system (RISS) and PubMed were searched to identify studies with randomized and non-randomized controlled trials. As the final outcome, 320 publications were identified and 18 studies met the inclusion and exclusion criteria. All studies were assessed for the quality of study using Cochrane's risk of bias. RESULTS: Sixteen studies met the inclusion criteria, in which meta-analysis had been conducted to examine the effectiveness of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI. Meta-analysis based on a random effect model showed that the cardiopulmonary physiotherapy was beneficial in improving the cardiopulmonary function, metabolism, inflammatory markers, and quality of life. In particular, there was a significant effect on the peak oxygen uptake (effect size 5.30%; 95% confidence interval 3.62~6.97). Cardiopulmonary physiotherapy for a during period of 6 weeks or more was effective in significantly improving the cardiopulmonary function and metabolism function in a subgroup analysis, but cardiopulmonary physiotherapy for less than 6 weeks was not effective. CONCLUSION: Cardiopulmonary physiotherapy has positive effects on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI.

Effectiveness of worksite-based dietary interventions on employees' obesity: a systematic review and meta-analysis

  • Park, Seong-Hi;Kim, So-Young
    • Nutrition Research and Practice
    • /
    • v.13 no.5
    • /
    • pp.399-409
    • /
    • 2019
  • BACKGROUND/OBJECTIVES: This study was designed to provide scientific evidence on the effectiveness of worksite-based dietary intervention to reduce obesity among overweight/obese employees. MATERIALS/METHODS: Electronic search was performed using Ovid Medline, Embase, Cochrane Library, and CINAHL databases. The keywords used were "obesity," "nutrition therapy," and "worksite." The internal validity of the randomized controlled trials (RCTs) was assessed using the Cochrane's Risk of Bias. Meta-analysis of selected studies was performed using Review Manager 5.3. RESULTS: A total of seven RCTs with 2,854 participants were identified. The effectiveness of dietary interventions was analyzed in terms of changes in weight, body mass index (BMI), total cholesterol, and blood pressure. The results showed that weight decreased with weighted mean difference (WMD) of -4.37 (95% confidence interval (CI): -6.54 to -2.20), but the effectiveness was statistically significant only in short-term programs < 6 months (P = 0.001). BMI also decreased with WMD of -1.26 (95% CI: -1.98 to -0.55), but the effectiveness was statistically significant only in short-term programs < 6 months (P = 0.001). Total cholesterol decreased with WMD of -5.57 (95% CI: -9.07 to -2.07) mg/dL, demonstrating significant effectiveness (P = 0.002). Both systolic (WMD: -4.90 mmHg) and diastolic (WMD: -2.88 mmHg) blood pressure decreased, demonstrating effectiveness, but with no statistical significance. CONCLUSIONS: The worksite-based dietary interventions for overweight/obese employees showed modest short-term effects. These interventions can be considered successful because weight loss was below approximately 5-10 kg of the initial body weight, which is the threshold for the management of obesity recommended by the Scottish Intercollegiate Guideline Network (SIGN).

A Study on the Combination Effect of Herbal Medicine and Western Medicine on BPSD in Patients with Alzheimer's Disease: A Systematic Review (알츠하이머병 환자의 이상행동심리증상(BPSD)에 대한 한약과 양약의 병용 효과에 대한 연구: 체계적 문헌 고찰)

  • Kim, Man-Gi;Chang, Seok-Joo;Hong, Min-Ho;Kim, Geun-Woo;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
    • /
    • v.31 no.4
    • /
    • pp.301-314
    • /
    • 2020
  • Objectives: The purpose of this study was to provide clinical evidence to support the use of herbal medicine combined with western medicine for BPSD. Methods: Studies were identified by searching CNKI, Pubmed, EMBASE, Cochrane Library, SCIENCEON, RISS, KMbase, KISS, OASIS. Literature searches of Chinese, English, and Korean databases were performed. Two authors independently extracted the data and evaluated the quality of each study. Results: The literature search identified 203 articles. Of these, 7 were selected for the analysis. The risk of bias in most studies was unclear. The most frequently used diagnostic tools were the NINCDS-ADRDA and DSM-IV. The most commonly used results indicator was NPI. In 6 of the 7 papers, combination treatment (herbal & Western medicine) was statistically significantly more effective than single treatment (Western medicine alone) for BPSD. No significant adverse events were reported. Conclusions: Herbal medicine in combination with Western medicine is more effective for treating BPSD than Western medicine alone. However, the quality of the studies used in this study was uncertain and the sample size was too small. Based on the findings of this study, more high-quality clinical trials are needed to confirm the efficacy of combination treatment.

Recent Research Trends of Acupuncture for Wrinkle Treatment (주름 개선을 위한 침 연구의 현황분석)

  • Jung, Hyeon-Suk;Kim, Tae-Jun;Park, Ji-Yeun
    • Korean Journal of Acupuncture
    • /
    • v.38 no.2
    • /
    • pp.62-74
    • /
    • 2021
  • Objectives : The aim of this study is to analyze the effect of acupuncture and the details of acupuncture treatment methods on skin wrinkles. Methods : Search was conducted in Pubmed, KISS, and NDSL databases for acupuncture studies on skin wrinkles. The detailed therapeutic techniques of acupuncture used for skin wrinkles and the effect of acupuncture on skin wrinkle improvement were analyzed. Then, the study results using the same indicator were compared through meta-analysis in order to compare the effects of acupuncture with the control group. The quality of randomized controlled trials (RCTs) was assessed using the risk of bias (ROB) assessment tool (Ver. 1.0, Cochrane Collaboration). Results : A total of 10 RCTs and 19 case series were included in this study. The most frequently used therapeutic technique for skin wrinkle improvement was Microneedle therapy system (MTS, n=19), and they were mostly used with aesthetic solutions (13 out of 19 studies). Skin wrinkle related indexes were most commonly used to evaluate skin wrinkle improvement (n=14). Panax Ginseng pharmacopuncture showed the most remarkable effect in improving the range of skin wrinkles and the depth of skin wrinkles. MTS+epidermal growth factor improved the levels of skin hydration, skin elasticity, and variation of skin pigment the most. MTS+Endothelial precursor cell improved the number of skin melanin the most. Three RCTs included in the meta-analysis showed moderate ROB on average. Conclusions : Acupuncture treatment was effective in improving skin wrinkles. However, a precise study design using unified indicators and appropriate controls needs to be performed in further studies in order to establish more convincing evidence of the effectiveness of acupuncture for improving skin wrinkles.

Effects of Second Victim Experiences after Patient Safety Incidents on Nursing Practice Changes in Korean Clinical Nurses: The Mediating Effects of Coping Behaviors (환자안전사건과 관련된 임상간호사의 이차피해경험이 간호실무변화에 미치는 영향: 대처의 매개효과)

  • Jeong, Seohee;Jeong, Seok Hee
    • Journal of Korean Academy of Nursing
    • /
    • v.51 no.4
    • /
    • pp.489-504
    • /
    • 2021
  • Purpose: This study was investigated the mediating effect of coping behaviors in the relationship between the second victim experiences after patient safety incidents and the nursing practice changes. Methods: A cross-sectional survey was performed using structured questionnaires. Participants were 218 clinical nurses in general tertiary hospitals in South Korea. Data were collected through an online survey and snowball sampling from August 11 to September 6 2020. Data were analyzed using SPSS 23.0 program. A mediation analysis was performed using multiple regression and a simple mediation model applying the PROCESS macro with 95% bias-corrected bootstrap confidence interval. Results: The mean scores of second victim experiences was 3.41/5. Approach coping (β = .55, p < .001) and the avoidant coping (β = - .23, p = .001) showed mediation effects in the relationship between second victim experiences and constructive change in nursing practice. Avoidant coping (β = .29, p < .001) showed a mediation effect in the relationship between second victim experiences and defensive change in nursing practice. Conclusion: Coping behaviors has a mediating effect on the relationship between second victim experiences and nursing practice changes. To ensure that nurses do not experience second victim, medical institutions should have a culture of patient safety that employs a systematic approach rather than blame individuals. They also need to develop strategies that enhance approach coping and reducing avoidant coping to induce nurses' constructive practice changes in clinical nurses in experiencing second victims due to patient safety incidents.

Review on the Objective Effect and Mechanism Studies of Herbal Medicine, Acupuncture and Moxibustion Treatment for Irritable Bowel Syndrome Patients (과민성 대장증후군 환자를 대상으로 수행된 한약 및 침구치료의 객관적 효과와 기전 연구에 대한 문헌고찰)

  • Noh, Hyun Deok;Kim, Min Jeong;Cho, Im Hak;Kim, So Yeon
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.35 no.5
    • /
    • pp.199-209
    • /
    • 2021
  • The purpose of this study was to explore objective indicators(outcomes) which are used to evaluate clinical efficacy and figure out the mechanisms of herbal medicine, acupuncture and moxibustion treatment for Irritable bowel syndrome(IBS). We searched randomized controlled trials(RCTs) that mediated with herbal medicine, acupuncture and moxibustion treatment for IBS and used objective indicators for outcome from November 1, 2020 to December 31, 2020. The RCTs that were published in Korean, English and Chinese were included in this study. The selected literatures were analyzed about methods of result measurement and assessed by Cochrane's risk of bias(RoB). Total 18 RCTs were included in this study. There were lots of objective indicators for result measurement; the concentration of hormones in blood and neurotransmitters, the sensitivity of rectum, the functional assessment of central nerve and autonomic nerve system, the change of intestinal flora, the concentration of serum cytokines. Various objective indicators can be used to evaluate the clinical efficacy of with herbal medicine, acupuncture and moxibustion treatment for IBS, but due to the limitations of the quality of the included studies, systematic review and meta-analysis will be needed.

Acupotomy for Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis (수근관증후군에 대한 도침치료의 효과: 체계적 문헌 고찰과 메타분석)

  • Jeong, Jae-Min;Sul, Jae-Uk;Kim, Seon-Jong;Seon, Yun-Gwon;Choi, Ji-Min;Noh, Hui-Jeong;Choi, Jin-Bong
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.32 no.3
    • /
    • pp.55-64
    • /
    • 2022
  • Objectives The objective of this study was to assess the effectiveness of acupotomy for carpal tunnel syndrome. Methods Based on seven domestic and foreign databases. We analyzed the randomized controlled trials using acupotomy for carpal tunnel syndrome. The treatment group was treated with acupotomy and the control group was no restrictions on treatment methods. Results In this study, the effect of acupuncture treatment for carpal tunnel syndrome was investigated. Each study reported that acupotomy could be an effective treatment for carpal tunnel syndrome. However, as a result of meta-analysis of Levine carpal tunnel syndrome questionnaire scores, visual analog scale, and sensory nerve conduction velocity, the results were more clinically significant than those of the control group. Due to the small number of randomized controlled trial studies and the nature of acupotomy treatment, blinding of interventions was impossible, resulting in a high risk of bias. Conclusions In this regard, it is thought that well-planned randomized controlled studies on patients with carpal tunnel syndrome are needed in the future to secure the clinical evidence for acupotomy treatment.

Survival of surface-modified short versus long implants in complete or partially edentulous patients with a follow-up of 1 year or more: a systematic review and meta-analysis

  • Medikeri, Raghavendra Shrishail;Pereira, Marisca Austin;Waingade, Manjushri;Navale, Shwetambari
    • Journal of Periodontal and Implant Science
    • /
    • v.52 no.4
    • /
    • pp.261-281
    • /
    • 2022
  • Purpose: Short implants are a potential alternative to long implants for use with bone augmentation in atrophic jaws. This meta-analysis investigated the survival rate and marginal bone level (MBL) of surface-modified short vs. long implants. Methods: Electronic and manual searches were performed for articles published between January 2010 and June 2021. Twenty-two randomized controlled trials (RCTs) comparing surface-modified short and long implants that reported the survival rate with at least 1 year of follow-up were selected. Two reviewers independently extracted the data, and the risk of bias and quality of evidence were evaluated. A quantitative meta-analysis was performed regarding survival rate and MBL. Results: The failure rates of surface-modified short and long implants differed significantly (risk ratio, 2.28; 95% confidence interval [CI], 1.46, 3.57; P<0.000). Long implants exhibited a higher survival rate than short implants (mean follow-up, 1-10 years). A significant difference was observed in mean MBL (mean difference=-0.43, 95% CI, -0.63, -0.23; P<0.000), favoring the short implants. Regarding the impact of surface treatment in short and long implants, for hydrophilic sandblasted acid-etched (P=0.020) and titanium oxide fluoride-modified (P=0.050) surfaces, the survival rate differed significantly between short and long implants. The MBL differences for novel nanostructured calcium-incorporated, hydrophilic sandblasted acid-etched, and dual acid-etched with nanometer-scale calcium phosphate crystal surfaces (P=0.050, P=0.020, and P<0.000, respectively) differed significantly for short vs. long implants. Conclusions: Short surface-modified implants are a potential alternative to longer implants in atrophic ridges. Long fluoride-modified and hydrophilic sandblasted acid-etched implants have higher survival rates than short implants. Short implants with novel nanostructured calcium-incorporated titanium surfaces, hydrophilic sandblasted acid-etched surfaces, and dual acid-etched surfaces with nanometer-scale calcium phosphate crystals showed less marginal bone loss than longer implants. Due to high heterogeneity, the MBL results should be interpreted cautiously, and better-designed RCTs should be assessed in the future.