• Title/Summary/Keyword: Data Bias

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Research on the Actual Condition of Shape and Make-up of Peanut-Shaped Cloth Diaper for Baby on Market (시판중인 유아용 땅콩기저귀의 형태와 구성에 관한 실태조사)

  • Lee, Jung-Soon;Han, Gyung-Hee;Koo, Mi-Ran
    • Journal of Fashion Business
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    • v.15 no.4
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    • pp.122-134
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    • 2011
  • The peanut-shaped cloth diaper has cut uncomfortable crotch region off the square-shaped cloth diaper into a peanut-shape, and finished the edge by bias with multi-layers of fabric. This study has the purpose on providing the basic data for designing the peanut-shaped cloth diaper. For this purpose, the peanut-shaped cloth diapers on market were collected and analyzed by their shape and size, and also the patterns and differences in making were compared. 26 products from 17 brands were collected as samples. The analysis factors are the shape and size of the peanut-shaped cloth diaper, and characteristics and patterns in making. Among the samples, only 3 diapers were straight-shaped; the rest of them were peanut-shaped. The size difference between the big and small peanut-shaped cloth diapers was very large; the total length of the small one was 36.5cm-39cm which was very common, and the total length of the big one was more than 44cm. All diapers had longer width in the back than the front. The width of the front and back was different for each sample, therefore, it seemed to have some difficulties to set the standard. The peanut-shaped cloth diaper had different make-up depending on its characteristics including. absorbance, washing and drying. It was usually made by cotton woven of diamond jacquard or knit, and finished the edge by woven bias or knit bias. The peanut-shaped cloth diapers were various including a sheet of diaper, two sheets of diapers fixed with velcro, three sheets of diapers, and etc. For the patterns of the diapers, only two samples out of all had three dimensional shape, and the rest were produced using flat shape. There were no distinction between the diapers of girls and boys. Therefore, it is necessary to make the product based on scientific data about the peanut-shaped cloth diaper.

Analyzing Common Method Bias of the Korean Empirical Studies on Technology Acceptance Model (한국 TAM 실증연구의 동일방법편의 분석)

  • Baek, Sang-Yong
    • The Journal of Information Systems
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    • v.21 no.1
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    • pp.1-17
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    • 2012
  • Common Method Bias(CMB) may cause the potential inflation of correlations between measures assessed via the same method. The problem of CMB has been well known in behavioral sciences because the survey method with self-reporting is vulnerable to CMB. Thus, the discussion on CMB is still ongoing in the MIS research in US. However, in Korea, the MIS research has never paid attention on the CMB problem. The purpose of this study is to examine the CMB problem in the Korean MIS research. To evaluate the effect of CMB, empirical studies on Technology Acceptance Model(TAM) are selected because (1) TAM is one of the MIS research areas studied intensively, (2) TAM is a theoretical model well supported by the existing empirical studies so that the result of this study would have a great ripple effect when the CMB problem turned out to be serious, (3) CMB is domain-specific. 47 TAM samples (out of 45 studies) from three Korean Journals were selected and the relevant data were collected such as correlation matrixes and the measures of the dependent variable. To find and evaluate the size of CMB, two analytic methods (Marker-Variable Technique and Method-Method Pair Technique) are employed. The result showed that there exists CMB in the Korean studies but the problem is not so serious to distort the empirical testing, compared with that of US studies. However, considering that CMB can contaminate the testing results, Korean MIS researchers should explicitly deal with the problem in designing empirical studies and collecting data.

Sensitivity Analysis of Global Wind-Wave Model (전지구 파랑 예측시스템의 민감도 분석)

  • Park, Jong Suk;Kang, KiRyong
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.5
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    • pp.333-342
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    • 2012
  • We studied the characteristics of spatial distribution of global wave height and carried out the modelsensitivity test by changing the input field, model resolution and physical factor (effective wind factor) since the spatial and temporal resolution in wind wave forecasting is one of most important factors. Comparisons among the different cases, and also between model, buoy and satellite data have been made. As a results of the wind-wave model run using the high resolution wind field, the bias of significant wave height showed the positive tendency and the Root-Mean Square Error(RMSE) was a bit decreased based on the comparison with buoy data. When the model resolution was changed to higher, the bias and RMSE was increased, and as the effective wind factor was smaller than default value(= 1.4) the bias and RMSE showed also decreasing pattern.

Comparisons of Middle- and Old-Aged Drivers' Recognition for Driving Scene Elements using Sensitivity, Response Bias, and Response Time (중년 및 고령운전자의 운전장면 개별요소에 대한 재인기억 차이: 민감도, 반응기준 및 반응시간 비교)

  • Lee, Jaesik
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.3185-3199
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    • 2018
  • Middle- and old-aged driver's capability in recognition for driving scene elements was compared. Central and ambient stimuli were selected from natural driving scene and sensitivity, bias and reaction time were measured as dependent measures. The results are as follows. First, in general, older drivers showed lower sensitivity than middle-aged drivers. In particular, the older drivers' sensitivity was significantly lower for the ambient stimuli than central stimuli, whereas the middle-aged drivers showed no significant difference between the two types of stimuli. Second, the older drivers tended to show more lenient responses whereas the middle-aged drivers responded more conservatively. Third, the older drivers showed longer reaction time than the middle-aged drivers, in particular, in the responses of miss and correct rejection. This results suggested that the older drivers' retention for driving scene elements in their working memory may not be stable, which can be resulted in difficulties in rapid and accurate responses in a real life driving.

Effects of Simulation Program using Immersive Virtual Reality: Meta-analysis (몰입형 가상현실 시뮬레이션 프로그램의 효과: 메타분석)

  • Choi, Moon-Ji;Kim, Kyeng-Jin
    • Journal of the Korea Convergence Society
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    • v.12 no.3
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    • pp.381-388
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    • 2021
  • The purpose of this study is to analyze the effects of simulation program using virtual reality (VR). Examination of databases resulted in identification of 1,415 studies of which 3 satisfied the inclusion data. Data analysis was performed using R version 4.0.2 to calculate the effect sizes, explore possible causes of heterogeneity, and check for publication bias, using a funnel plot. The mean effect size of the simulation program was medium (g=0.35), along with the skill performance (g=0.59), satisfaction (g=0.38), knowledge (g=0.21). Finally a funnel plot was produced to check for publication bias, but no significant bias was detected. Based on these findings, the simulation program using VR affects nursing education.

Self-care in Patients with Atrial Fibrillation Based on the Theory of Unpleasant Symptoms (불쾌 증상 이론을 적용한 심방 세동 환자의 자가관리)

  • Kim, Min Young;Lee, Sun Hee;Park, Han Jong
    • Journal of Korean Clinical Nursing Research
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    • v.28 no.1
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    • pp.23-33
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    • 2022
  • Purpose: This study aimed to identify the relationships among disease severity, anxiety, depression, social support, unpleasant symptoms and self-care among patients with atrial fibrillation based on the unpleasant symptom theory, and to examine the mediating effects of unpleasant symptoms. Methods: A cross-sectional study was conducted. The participants were 216 patients with atrial fibrillation who were being followed up on an outpatient basis at a university hospital in Seoul. Data were collected from November 1, 2020 to June 30, 2021, using self-report questionnaires. Data were analyzed using IBM SPSS/WIN 27.0 and PROCESS macro with 95% bias-corrected bootstrap confidence interval(CI). Results: The average age of participants in this study was 66.0years. Disease severity (β=10.19, p<.001) and depression (β=1.53, p<.001) had significant positive relationships with unpleasant symptoms. Also, unpleasant symptoms (β=-0.03, p=.006) had a negative relationship with physical activity, which is a subscale of self- care. Social support (β=0.06, p<.001) was positively related with physical activity. Unpleasant symptoms showed a mediation effect in the relationship between disease severity and physical activity (Bias corrected bootstrap CI -0.65, -0.04). Depression had an indirect effect on physical activity that was mediated by unpleasant symptoms (Bias corrected bootstrap CI -0.11, -0.00). Conclusion: The findings of this study suggest that integrated strategies including physical, psychological, and social factors should be considered to promote self-care in patients with atrial fibrillation.

A novel framework for correcting satellite-based precipitation products in Mekong river basin with discontinuous observed data

  • Xuan-Hien Le;Giang V. Nguyen;Sungho Jung;Giha Lee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.173-173
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    • 2023
  • The Mekong River Basin (MRB) is a crucial watershed in Asia, impacting over 60 million people across six developing nations. Accurate satellite-based precipitation products (SPPs) are essential for effective hydrological and watershed management in this region. However, the performance of SPPs has been varied and limited. The APHRODITE product, a unique gauge-based dataset for MRB, is widely used but is only available until 2015. In this study, we present a novel framework for correcting SPPs in the MRB by employing a deep learning approach that combines convolutional neural networks and encoder-decoder architecture to address pixel-by-pixel bias and enhance accuracy. The DLF was applied to four widely used SPPs (TRMM, CMORPH, CHIRPS, and PERSIANN-CDR) in MRB. For the original SPPs, the TRMM product outperformed the other SPPs. Results revealed that the DLF effectively bridged the spatial-temporal gap between the SPPs and the gauge-based dataset (APHRODITE). Among the four corrected products, ADJ-TRMM demonstrated the best performance, followed by ADJ-CDR, ADJ-CHIRPS, and ADJ-CMORPH. The DLF offered a robust and adaptable solution for bias correction in the MRB and beyond, capable of detecting intricate patterns and learning from data to make appropriate adjustments. With the discontinuation of the APHRODITE product, DLF represents a promising solution for generating a more current and reliable dataset for MRB research. This research showcased the potential of deep learning-based methods for improving the accuracy of SPPs, particularly in regions like the MRB, where gauge-based datasets are limited or discontinued.

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Add-on Effect of Herbal Bath Combined with Acitretin Treatment in Patients with Psoriasis : Systemic Review and Meta-analysis (건선 환자에서 아시트레틴 치료에 추가한 한방 약욕 효과 : 체계적 문헌 고찰과 메타 분석)

  • Seoyeon Jun;Soojin Park;Jieun Lee;Kyuseok Kim
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.36 no.3
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    • pp.74-98
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    • 2023
  • Objectives : This study aims to evaluate the add-on effect of herbal bath combined with acitretin in patients with psoriasis. Methods : We searched randomized controlled trials(RCTs) reporting the effect of herbal bath and acitretin combined treatment for psoriasis in 10 electronic databases from their inception to January 2023. Study collection, data extraction, and risk of bias assessment were performed by two independent researchers. Data synthesis and risk of bias evaluation was conducted using Revman 5.4. Results : Ten RCTs with 1,008 subjects were included. Herbal bath and acitretin combined treatment group showed higher average total effective rate than acitretin alone group(RR 1.39; 95% CI: 1.15-1.68, P=0.0006, I2 =0%). Herbal bath and additional treatments such as phototherapy(NB-UVB) and oral herbal medicine, combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.81; 95% CI: 1.47-2.22, P<0.00001, I2 =43%). Herbal bath and phototherapy(NB-UVB) combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.51; 95% CI: 1.18-1.93, P=0.0009, I2 =0%). The overall risk of bias of the included studies was unclear or of high risks. Conclusions : This review showed that the add-on of herbal bath combined with acitretin treatment could be more effective than acitretin alone treatment in patients with psoriasis. However, because of few included studies, heterogeneity between studies, and insufficient quality of included studies, further well-designed RCTs are needed to confirm the add-on effect of herbal bath on psoriasis.

Estimation of BDI Volatility: Leverage GARCH Models (BDI의 변동성 추정: 레버리지 GARCH 모형을 중심으로)

  • Mo, Soo-Won;Lee, Kwang-Bae
    • Journal of Korea Port Economic Association
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    • v.30 no.3
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    • pp.1-14
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    • 2014
  • This paper aims at measuring how new information is incorporated into volatility estimates. Various GARCH models are compared and estimated with daily BDI(Baltic Dry Index) data. While most researchers agree that volatility is predictable, they differ on how this volatility predictability should be modelled. This study, hence, introduces the asymmetric or leverage volatility models, in which good news and bad news have different predictability for future. We provide the systematic comparison of volatility models focusing on the asymmetric effect of news on volatility. Specifically, three diagnostic tests are provided: the sign bias test, the negative size bias test, and the positive size bias test. From the Ljung-Box test statistic for twelfth-order serial correlation for the level we do not find any significant serial correlation in the unpredictable BDI. The coefficients of skewness and kurtosis both indicate that the unpredictable BDI has a distribution which is skewed to the left and significantly flat tailed. Furthermore, the Ljung-Box test statistic for twelfth-order serial correlations in the squares strongly suggests the presence of time-varying volatility. The sign bias test, the negative size bias test, and the positive size bias test strongly indicate that large positive(negative) BDI shocks cause more volatility than small ones. This paper, also, shows that three leverage models have problems in capturing the correct impact of news on volatility and that negative shocks do not cause higher volatility than positive shocks. Specifically, the GARCH model successfully reveals the shape of the news impact curve and is a useful approach to modeling conditional heteroscedasticity of daily BDI.

The Assessment of Risk of Bias on Randomised Controlled Trials of Oriental Medicine in Korea (한의학 관련 무작위배정비교임상연구의 비뚤림 위험 평가)

  • Lee, Yoon-Jae;Jang, Bo-Hyoung;Go, Ho-Yeon;Hyun, Min-Kyung;Park, Sun-Young;Lee, Chang-Hoon;Kim, Jin-Sung;Cho, Ki-Ho
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.4
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    • pp.105-113
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    • 2011
  • Objectives: To examine the current status of clinical research in oriental medicine, and to assess 'risk of bias'(ROB) of randomized clinical trials(RCTs) in oriental medicine in Korea. Methods: Special committee for EBM, KOMS(Korean Oriental Medicine Society) reviewed 17 journals related to oriental medicine in Korea (from the first issue to May 2010), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2010), and PubMed (1966 to May 2010). Then we selected eligible RCTs in terms of oriental medicine, and assessed 'risk of bias'. Results: We reviewed 12,653 articles from the 17 journals, and 41 articles from CENTRAL and PubMed. After non-clinical articles were excluded, 1,004 articles were left. Among them, the number of eligible studies in terms of oriental medicine was 306. In these eligible studies, 130 were RCTs. Of RCTs, 69 were on acupuncture, 25 on herbal medicine. The proportion of 'unclear' is high in the criteria of 'Allocation concealment', 'Blinding of participants and personnel', 'Blinding of outcome assessment' and 'Other bias'. On the other hand, 'low' has high in the criteria of 'Incomplete outcome data' and 'Selective reporting'. Conclusions: Risk of bias on oriental medicine is unclear in terms of 'allocation concealment' and 'blinding'. For high-quality research in oriental medicine, further research should be needed on randomization and blinding in the RCTs.