• Title/Summary/Keyword: Data Bias

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Improving Initial Abstraction Method of NRCS-CN for Estimating Effective Rainfall (유효우량 산정을 위한 NRCS-CN 모형의 초기손실량 산정방법 개선)

  • Park, Dong-Hyeok;Ajmal, Muhammad;Ahn, Jae-Hyun;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.48 no.6
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    • pp.491-500
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    • 2015
  • In order to improve the runoff estimation accuracy of the Natural Resources Conservation Service (NRCS) curve number (CN) model, this study incorporated rainfall and maximum potential retention as contributors for initial abstraction. The modification was proposed based on 658 rank-order data of rainfall and subsequent runoff from 15 watersheds. The NRCS-CN model (M1), one of its inspired modified model (M2), and the proposed model (M3) were analyzed employing different CN approaches. Using tabulated, calculated and least squares fitted CNs ($CN_T$, $CN_C$, $CN_{LSF}$, respectively), the models' performances were evaluated based on Root Mean Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), and Percent Bias (PBIAS). Applications of model M1, M2, and M3, respectively exhibited watershed cumulative mean [RMSE (23.60, 18.12, 16.04), NSE (0.54, 0.73, 0.79), and PBIAS (36.54, 20.25, 12.00)]. Similarly, using CNC (for M1 and M2 model) and $CN_{LSF}$ (for M3 model), the performance of three models respectively were assessed based on watershed cumulative mean [RMSE (17.17, 15.88, 13.82), NSE (0.76, 0.80, 0.85), and PBIAS (3.06, 4.47, 0.11)]. The proposed model (M3) that linked all of the NRCS-CN variants showed more statistically significant agreement between the observed and estimated data.

Mathematical modeling of growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds (적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델)

  • Choi, Soo Yeon;Ryu, Sang Don;Park, Byeong-Yong;Kim, Se-Ri;Kim, Hyun-Ju;Lee, Seungdon;Kim, Won-Il
    • Food Science and Preservation
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    • v.24 no.6
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    • pp.778-785
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    • 2017
  • This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

Characteristics of Speckle Errors of SeaWiFS Chlorophyll-α Concentration in the East Sea (동해 SeaWiFS 클로로필-α 농도의 스펙클 오차 특성)

  • Chae, Hwa-Jeong;Park, Kyung-Ae
    • Journal of the Korean earth science society
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    • v.30 no.2
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    • pp.234-246
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    • 2009
  • Characteristics of speckle errors of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-${\alpha}$ concentration were analyzed, and its causes were investigated by using SeaWiFS data in the East Sea from September 1997 to December 2007. The speckles with anomalously high concentrations were randomly distributed and showed remarkably high bias of greater than $10mg/m^3$, compared with their neighboring pixels. The speckles tended to appear frequently in winter, which might be related to cloud distribution. Ten-year averaged cloudiness of winter was much higher over the southeastern part, with frequent speckles, than the northwestern part of the East Sea. Statistical analysis results showed that the number of the speckles was increased as cloudiness increased. Normalized water-leaving radiance of the speckle pixel was considerably low at the short wavelengths (443, 490, and 510 nm), whereas the radiance at 555 nm band was normal. These low measurements produced extraordinarily high concentration from the chlorophyll-${\alpha}$ estimation formula. This study presented the speckle errors of SeaWiFS chlorophyll-${\alpha}$ concentration in the East Sea and suggested that more reliable chlorophyll-${\alpha}$ data based on appropriate ocean color remote sensing techniques should be used for the oceanic application researches.

Improved Socio-Economic Status of a Community Population Following Schistosomiasis and Intestinal Worm Control Interventions on Kome Island, North-Western Tanzania

  • Mwanga, Joseph R.;Kaatano, Godfrey M.;Siza, Julius E.;Chang, Su Young;Ko, Yunsuk;Kullaya, Cyril M.;Nsabo, Jackson;Eom, Keeseon S.;Yong, Tai-Soon;Chai, Jong-Yil;Min, Duk-Young;Rim, Han-Jong;Changalucha, John M.
    • Parasites, Hosts and Diseases
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    • v.53 no.5
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    • pp.553-559
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    • 2015
  • Research on micro-level assessment of the changes of socio-economic status following health interventions is very scarce. The use of household asset data to determine wealth indices is a common procedure for estimating socio-economic position in resource poor settings. In such settings information about income is usually lacking, and the collection of individual consumption or expenditure data would require in-depth interviews, posing a considerable risk of bias. In this study, we determined the socio-economic status of 213 households in a community population in an island in the north-western Tanzania before and 3 year after implementation of a participatory hygiene and sanitation transformation (PHAST) intervention to control schistosomiasis and intestinal worm infections. We constructed a household 'wealth index' based housing construction features (e.g., type of roof, walls, and floor) and durable assets ownership (e.g., bicycle, radio, etc.). We employed principal components analysis and classified households into wealth quintiles. The study revealed that asset variables with positive factor scores were associated with higher socio-economic status, whereas asset variables with negative factor scores were associated with lower socio-economic status. Overall, households which were rated as the poorest and very poor were on the decrease, whereas those rated as poor, less poor, and the least poor were on the increase after PHAST intervention. This decrease/increase was significant. The median shifted from -0.4376677 to 0.5001073, and the mean from -0.2605787 (SD; 2.005688) to 0.2605787 (SD; 1.831199). The difference in socio-economic status of the people between the 2 phases was highly statistically significant (P<0.001). We argue that finding of this study should be treated with caution as there were other interventions to control schistosomiasis and intestinal worm infections which were running concurrently on Kome Island apart from PHAST intervention.

Systematic Review of Short Stature and Growth Related Qualitative Researches (저신장 및 성장과 관련된 질적연구에 대한 체계적 문헌 고찰)

  • Kim, Hye Jin;Jeon, Chae Heun;Roh, Min Yeong;Han, Ye Ji;Kim, Hyun Ho;Cheong, Moon Joo;Leem, Jung Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.33 no.4
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    • pp.74-88
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    • 2019
  • Objectives The aim of this study is systematic evaluation of the quality of qualitative studies related to short stature. It will be utilized as fundamental data for future qualitative research about Korean Medicine Pediatrics treatment for short stature. Methods We searched qualitative studies related to short stature in the Pubmed. Two researchers independently assessed the quality of the qualitative researches by using Consolidated criteria for reporting qualitative research (COREQ) and Critical Appraisal Skills Program (CASP). We also qualitatively synthesized theme of each included studies. We presented integrated theme and categories with in vivo coding about qualitative research about short stature. Results A total of 47 papers were screened and 7 papers were finally selected. In the quality assessment using COREQ, detalied information about the researchers, methods of approach, reasons for non-participation, presence of non-participants, participant's review of the transcript, and participant's review of the findings were insufficient. In the quality evaluation using CASP, there were lack of justifications for the research methods, description method of research, and bias in process of data analysis. The findings were synthesized into three themes: fixed idea about height, discomfort caused by small stature and personal coping strategy with stress caused by short stature. Conclusions In further qualitative research, it is necessary to report the research according to COREQ and CASP checklist. It is also necessary to understand the stress and coping strategies to short stature of patients, We need to develop a social management strategy for short stature.

A Study on Photovoltaic Panel Monitoring Using Sentinel-1 InSAR Coherence (Sentinel-1 InSAR Coherence를 이용한 태양광전지 패널 모니터링 효율화 연구)

  • Yoon, Donghyeon;Lee, Moungjin;Lee, Seungkuk
    • Korean Journal of Remote Sensing
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    • v.37 no.2
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    • pp.233-243
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    • 2021
  • Photovoltaic panels are hazardous electronic waste that has heavy metal as one of the hazardous components. Each year, hazardous electronic waste is increasing worldwide and every heavy rainfall exposes the photovoltaic panel to become the source of heavy metal soil contamination. the development needs a monitoring technology for this hazardous exposure. this research use relationships between SAR temporal baseline and coherence of Sentinel-1 satellite to detected photovoltaic panel. Also, the photovoltaic plant detection tested using the difference between that photovoltaic panel and the other difference surface of coherence. The author tested the photovoltaic panel and its environment to calculate differences in coherence relationships. As a result of the experiment, the coherence of the photovoltaic panel, which is assumed to be a permanent scatterer, shows a bias that is biased toward a median value of 0.53 with a distribution of 0.50 to 0.65. Therefore, further research is needed to improve errors that may occur during processing. Additionally, the author found that the change detection using a temporal baseline is possible as the rate of reduction of coherence of photovoltaic panels differs from those of artificial objects such as buildings. This result could be an efficient way to continuously monitor regardless of weather conditions, which was a limitation of the existing optical satellite image-based photovoltaic panel detection research and to understand the spatial distribution in situations such as photovoltaic panel loss.

Impacts of Relative Advantage of Fast Food Restaurant's O2O Service and Consumer Involvement on Consumer Engagement, and Store Loyalty: Focused on MZ Generationsin Untact Consumption Era

  • LEE, Young-Eun;LEE, Yong-Ki
    • The Korean Journal of Franchise Management
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    • v.11 no.2
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    • pp.41-51
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    • 2020
  • Purpose: Fast food franchise companies are trying a variety of innovative services to increase their competitiveness in response to changes in population composition in the fast food market and rapid changes in consumption trends due to technological development. From this point of view, franchise companies that have focused on offline store operations are providing O2O (offline to online) service as a core service for customer convenience. This new attempt is a strategy to increase loyalty by applying an interaction method based on understanding the characteristics of new generation consumers. However, existing studies are focused on the relationship between O2O service and acceptance, so very little is known about how O2O service affects customer loyalty. Therefore, this study examines the impacts of customer involvement and relative advantages of fast food O2O service on customer brand engagement (cognitive and affective engagement) and store loyalty for MZ(Millennials - Z) generations. Research design, data, and methodology: In order to achieve the purposes of this research, several hypotheses were developed. The data were collected from 247 questionnaires in their 16-30s and were analyzed using SPSS 22.0 and SmartPLS 3.0 program. Measurement model analysis was carried out to assess convergent and discriminant validity. Also, common method bias was tested using the values of VIF (variance inflation factor). The hypotheses was tested using structural equation modeling. Result: First, involvement has a positive effect on cognitive and affective engagement. Second, relative advantages have has a positive effect on cognitive and affective engagement. Third, cognitive influences affective engagement. Finally, both cognitive and affective engagement affect store loyalty, but affective engagement has a stronger effect on store loyalty than cognitive engagement. Conclusions: In the process of consumer-brand interaction, it was confirmed that store loyalty was influenced by cognitive and affective engagement sequentially. However, the results show that affective engagement has a relatively stronger on store loyalty than cognitive engagement. Therefore, it is necessary to establish an O2O service strategy to maintain long-term loyal customers by inducing cognitive participation with high-involved consumer, as well as affective interaction, in order to obtain new customers and increase customer loyalty.

Development and Verification of NEMO based Regional Storm Surge Forecasting System (NEMO 모델을 이용한 지역 폭풍해일예측시스템 개발 및 검증)

  • La, Nary;An, Byoung Woong;Kang, KiRyong;Chang, Pil-Hun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.373-383
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    • 2020
  • In this study we established an operational storm-surge system for the northwestern pacific ocean, based on the NEMO (Nucleus for European Modeling of the Ocean). The system consists of the tide and the surge models. For more accurate storm surge prediction, it can be completed not only by applying more precise depth data, but also by optimal parameterization at the boundaries of the atmosphere and ocean. To this end, we conducted several sensitivity experiments related to the application of available bathymetry data, ocean bottom friction coefficient, and wind stress and air pressure on the ocean surface during August~September 2018 and the case of typhoon SOULIK. The results of comparison and verification are presented here, and they are compared with POM (Princeton Ocean Model) based Regional Tide Surge forecasting Model (RTSM). The results showed that the RTSM_NEMO model had a 29% and 20% decrease in Bias and RMSE respectively compared to the RTSM_POM model, and that the RTSM_NEMO model had a lower overall error than the RTSM_POM model for the case of typhoon SOULIK.

Impacts of Perceived Innovativeness of Convenience Store on Consumer Brand Engagement and Store Loyalty (편의점의 혁신성이 인지적 인게지먼트와 정서적 인게이지먼트, 그리고 점포충성도에 미치는 영향)

  • LEE, Young-Eun;LEE, Yong-Ki
    • The Korean Journal of Franchise Management
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    • v.13 no.1
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    • pp.35-46
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    • 2022
  • Purpose: With the rapid changes in the technical development and the trend of consumption trend, the convenience store industry is facing an unprecedented competitive situation in the consumption environment where the boundary between online and offline is broken due to the stagnation of offline distribution channels and the spread of online shopping. The biggest innovation strategy of the major convenience store brands in recent years are introducing the O2O (Online to Offline) platform and presenting new products and services beyond the boundaries of online and offline to transform themselves into Omni Channel stores. The study is designed to analyze the effect of innovativeness of convenience store as a stimulus in O2O platform which customers perceive on store loyalty, the final response to external stimuli, through customer engagement with convenience store brands. Specifically, the innovativeness of convenience stores was divided into types of core activities in corporate marketing and focused on innovations in services, products(proposals), promotions and experiences. Research design, data, and methodology: Various hypotheses have been developed to achieve this research purpose. The data were collected from 1,128 questionnaires the age between 15 and 60 who had experience using retail store apps and delivery apps and were analyzed using SPSS 22.0 and SmartPLS 3.3.7 program. Measurement model analysis was carried out to assess convergent and discriminant validity. Also, common method bias was tested using the values of VIF (variance inflation factor). The hypotheses were tested using structural equation modeling with SmartPLS 3.3.7 program. Results: First, service innovation has a positive effect on cognitive engagement. Second, product, promotion and experience innovation have a positive effect on cognitive and affective engagement. Third, cognitive influences affective engagement. Finally, both cognitive and affective engagement affect store loyalty, but affective engagement has a stronger effect on store loyalty than cognitive engagement. Conclusions: All four types of innovation and cognitive engagement have a positive effect on emotional engagement, which has a stronger effect on store loyalty than cognitive engagement. Thus, while innovation can build loyalty through emotional engagement, innovation strategies must be designed and pursued with caution in terms of impact through cognitive engagement may not achieve the planned goals.

Punitiveness Toward Defendants Accused of Same-Race Crimes Revisited: Replication in a Different Culture (동인종 범죄로 기소된 피고인에 대한 엄벌주의적 판단의 재고찰: 다른 문화에서의 적용)

  • Lee, Jungwon;Khogali, Mawia;Despodova, Nikoleta M.;Penrod, Steven D.
    • Korean Journal of Forensic Psychology
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    • v.11 no.1
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    • pp.37-61
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    • 2020
  • Lee, Khogali, Despodova, and Penrod (2019) demonstrated that American participants whose races are different from a defendant and a victim rendered more punitive judgments against the defendant in a same-race crime (e.g., White observer-Black defendant-Black victim) compared to a cross-race crime (e.g., White observer-Black defendant-Hispanic victim). The aim of the current study was to test the replicability of their findings in a different country-South Korea. Study 1a failed to replicate the race-combination effect in South Korea with three new moderators-case strength, defendant's use of violence, and race salience. Study 1b was conducted with the same design of Study 1a in the United States to examine whether the failure of the replication in Study 1a was due to cultural differences between South Korea and the United States. However, Study 1b also failed to replicate the race-combination effect. Study 2 conducted a meta-analytic review of the data from Lee et al.'s (2019) study, along with the data from Study 1a and 1b and revealed that the race-salience manipulation in Study 1a and 1b might have caused the null results. We conclude that when people' races are different from both a defendant and a victim, they are likely to render more punitive judgments against the defendant in a same-race crime than a cross-race crime. However, the race-combination effect is only sustained when race-relevant issues are not salient in the crime.

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