• Journal of Korean Academy of Nursing
• /
• v.48 no.1
• /
• pp.50-58
• /
• 2018

Purpose: The purpose of this study was to examine the mediating effect of marital intimacy on the impact of uncertainty on the quality of life (QoL) of young breast cancer patients. Methods: This study used a pathway analysis with 154 young breast cancer cases in their early diagnosis stage at a medical center in Korea. Data were collected from November 2016 to February 2017 and analyzed using correlation analysis and pathway analysis. Results: Uncertainty, marital intimacy, and 4 sub-scales of QoL showed a significant correlation. Marital intimacy was directly affected by uncertainty (${\beta}=-.39$, p=.013) and 4 sub-scales of QoL were also affected by uncertainty. Among the 4 sub-scales of QoL, physical well-being (PWB) (${\beta}=.17$, p=.026), social well-being (SWB) (${\beta}=.49$, p=.010), and functional well-being (FWB) (${\beta}=.38$, p=.009) were affected by marital intimacy but emotional well-being (EWB) was not affected by it. The mediating effect of marital intimacy on the impact of uncertainty on QoL was confirmed. Marital intimacy showed a significant indirect effect on PWB (${\beta}=-.07$, p=.024), SWB (${\beta}=-.19$, p=.008), and FWB (${\beta}=-.15$, p=.005), and it means that marital intimacy has a partial mediating effect on the impact of uncertainty on PWB, SWB, and FWB. Conclusion: Effects of uncertainty on QoL was mediated by marital intimacy of young breast cancer patients in their early diagnosis stage. It suggests that marital intimacy needs to be considered in providing nursing intervention for young breast cancer patients.

• Journal of Information Technology Applications and Management
• /
• v.11 no.2
• /
• pp.15-27
• /
• 2004

Most software projects inevitably involve various types and degrees of uncertainty. Without proper risk assessment and coordination, software projects can easily run out of control and consume significant additional resource. Thus, risk management techniques are critical issues to information system researchers. Previous empirical studies of U.S. software firms support the adoption of development standardization and user requirement analysis techniques in risk-based software project management. Using data collected from software projects developed in Korea during 1999-2000, we conduct a comparative study to determine how risk management strategies impact software product and process performance in countries with dissimilar IT capabilities. In addition, we offer an alternative conceptualization of residual performance risk. We show that the use of residual performance risk as an intervening variable is inappropriate in IT developing countries like Korea where the role of late stage risk control remedies are critical. A revised model is proposed that generates more reliable empirical implications for Korean software projects.

• 한국전산유체공학회:학술대회논문집
• /
• 2010.05a
• /
• pp.28-31
• /
• 2010

In order to clarify the characteristics of power performance and uncertainty of a wind turbine, an investigation was performed in Hangyeong wind farm, Jeju island, Korea. Data were collected for 12 months from Feb. 2, 2008 to Jan. 1, 2009. This study was conducted on the base of the International standard, and observed the methods of mesurement and evaluation form IEC 61400-12. As a result, power performance curve was calculated by measured data and compared with the sixth unit of VESTAS V90-3.0MW in Hangyeong wind farms. In consequence of this paper, uncertainty was estimated from 7% to 14% on the range of the average wind speed from 4m/s to 11m/s.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.602-607
• /
• 2008

A technique for reliability-based design optimization(RBDO) is developed based on the Bayesian approach, which can deal with the epistemic uncertainty arising due to the limited number of data. Until recently, the conventional RBDO was implemented mostly by assuming the uncertainty as aleatory which means the statistical properties are completely known. In practice, however, this is not the case due to the insufficient data for estimating the statistical information, which makes the existing RBDO methods less useful. In this study, a Bayesian reliability is introduced to take account of the epistemic uncertainty, which is defined as the lower confidence bound of the probability distribution of the original reliability. In this case, the Bayesian reliability requires double loop of the conventional reliability analyses, which can be computationally expensive. Kriging based dimension reduction method(KDRM), which is a new efficient tool for the reliability analysis, is employed to this end. The proposed method is illustrated using a couple of numerical examples.

• New & Renewable Energy
• /
• v.6 no.2
• /
• pp.5-11
• /
• 2010

This paper reviews three commercial softwares for wind climate data analysis in wind resource assessment; WAsP/Observed Wind Climate, WindRose and Windographer. Windographer is evaluated as the best software because of its variety of input data format, analysis functions, easiness of user interface, etc. For a quantitative understanding of uncertainty depending on software selection, a benchmark is carried out with the met-mast observation dataset at the Gimnyeong Wind Turbine Performance Test Site. It is found that Weibull parameter calculation and air density correction have a dependency on the software so that such uncertainty should be considered when an analysis software is selected. It is confirmed that annual energy production calculated by WAsP using a statistical table of frequency of occurrence may have some error compared to a time-series calculation method used by the other softwares.

• Nuclear Engineering and Technology
• /
• v.52 no.4
• /
• pp.755-763
• /
• 2020

The critical flow phenomenon has been studied because of its significant effect for design basis accidents in nuclear power plants. Transition points from thermal non-equilibrium to equilibrium are different according to the geometric effect on the critical flow. This study evaluates the uncertainty parameters of the critical flow model for analysis of DBA (Design Basis Accident) with the MARS-KS (Multi-dimensional Analysis for Reactor Safety-KINS Standard) code used as an independent regulatory assessment. The uncertainty of the critical flow model is represented by three parameters including the thermal non-equilibrium factor, discharge coefficient, and length to diameter (L/D) ratio, and their ranges are determined using large-scale Marviken test data. The uncertainty range of the thermal non-equilibrium factor is updated by the MCDA (Model Calibration through Data Assimilation) method. The updated uncertainty range is confirmed using an LBLOCA (Large Break Loss of Coolant Accident) experiment in the LOFT (Loss of Fluid Test) facility. The uncertainty ranges are also used to calculate an LBLOCA of the APR (Advanced Power Reactor) 1400 NPP (Nuclear Power Plants), focusing on the effect of the PCT (Peak Cladding Temperature). The results reveal that break flow is strongly dependent on the degree of the thermal non-equilibrium state in a ruptured pipe with a small L/D ratio. Moreover, this study provides the method to handle the thermal non-equilibrium factor, discharge coefficient, and length to diameter (L/D) ratio in the system code.

• Journal of Korea Trade
• /
• v.27 no.5
• /
• pp.153-166
• /
• 2023

Purpose - This research empirically analyzes the influence of economic policy uncertainty and free trade agreements (FTAs) on bilateral trade volumes between Korea and its trading partners. The study investigates whether fluctuations in the Economic Policy Uncertainty Index (EPUI) for both Korea and its trading partners significantly impact trade volumes and whether the implementation of FTAs mitigates these effects. Design/methodology - The study employs dynamic panel data analysis using the system generalized method of moments (system GMM) estimation method to achieve its research objectives. It utilizes country-month-level panel data, including the EPUI, trade volume between Korea and its trading partner countries, and other pertinent variables. The use of system GMM allows for the control of potential endogeneity issues and the incorporation of country-specific and time-specific effects. Findings - The analysis yields significant results regarding the impact of economic policy uncertainty on Korea's exports and imports, particularly before the implementation of FTAs. An increase in the EPUI of trading partners leads to a notable increase in Korea's exports to them. Conversely, an increase in Korea's EPUI negatively affects its imports from trading partners. However, post-FTA implementation, the influence of each country's EPUI on trade volume is neutralized, with no significant difference observed. Originality/value - This research contributes to the existing literature by providing empirical evidence on the interaction effects between economic policy uncertainty and FTAs on bilateral trade volumes. The study's uniqueness lies in its examination of how FTAs mitigate the impact of economic uncertainty on trade relations between countries. The findings underscore the importance of trade agreements as mechanisms to address economic risks and promote international trade relations. In a world where global market uncertainties persist, these insights can aid policymakers in Korea and other countries in enhancing their trade cooperation strategies and navigating challenges posed by evolving economic landscapes.

• YAKHAK HOEJI
• /
• v.52 no.6
• /
• pp.480-487
• /
• 2008

We described an estimation of measurement uncertainty in quantitative analysis of 11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THCCOOH), the major metabolite of ${\Delta}^9$-tetrahydrocannabinol, in urine sample by solid-phase extraction (SPE) and GC/MS detection. The analytical results were compared and the different contributions to the uncertainty were evaluated. Inter-day and inter-person validation were performed using statistical analysis of several indicative factors. Measurement uncertainty associated with target analyte in real forensic samples was estimated using quality control (QC) data. Traceability of measurement was established through traceable standards, calibrated volumetric glassware and volume measuring device. The major factors of contribution to combined standard uncertainty, were calibration linearity, inter-day repeatability and inter-person reproducibility, while those associated with preparation of analytical standards and sampling volume were not so important considering the degree of contribution. Relative combined standard uncertainties associated with the described method was 12.05% for THCCOOH.

• Journal of Korean Academy of Nursing
• /
• v.24 no.4
• /
• pp.529-544
• /
• 1994

For most parents their child's illness and hospitalization is strssful. Internal stress and over anxiousness leads to uncertainty. Parents have a variety of ways of coping when faced with such stress factors, especialy when the child has cancer. The purpose of this study was to examine the relationship between uncertainty in illness and mastery and coping styles in parents of pediatric cancer patients, and further to identify differences between three groups of subjects. A cross-sectional descriptive correlational design was used in this study to investigate the relationship among the three groups. The sample was composed of 59 parents of children with cancer in pediatric wards in three hospitals in Seoul : 21 in Group 4 with a child newly diagnosed with cancer : 25 in Group B, with a child under treatment and rehospitalized with a relapse : and 13 in Group C, with a child with a terminal cancer, A formalized questionnaire which included demegrapic information and consisted of 75 items was used in this study ; The Parent Perception of Uncertainty Scale(PPUS) adapted form Mishel’s Uncertainty in Illness Scale, Pearlin & Schooler's Mastery Scale(MS) and Folkman & Lazarus’s Ways of Coping Checklist(WCC) were used to measure the variables : uncertainty in illness, mastery, and coping styles. A pretest was conducted on the questionnaire items for reliability. The results gathered were analyzed using SPSS /PC/sup +/. Data analysis included descriptive correltional statistics such as ANOVA, Pearson Correlation Coefficient, amd chi square test. The conclusions of this analysis are summarized as follows : 1. A higher level of uncertainty was seen among parents of children with terminal cancer. 2. The first hypothesis that uncertainty in illness would differ among the three groups was supported(F=4.182, P=.020). The second and third hypotheses that mastery and coping styles would differ among the three groups were not supported. There was a correlation between uncertainty, mastery, and coping styles which was positive, also there was a positive correlation between mastery and coping style(r=.3744, P<.001) but a negative correlation between uncertainty md mastery(r=-.4749, P<.01). From the above results, it can be concluded that prediciting and controlling uncertainty in illness by considering coping styles and mastery are necessary for improved, efficient nursing interventions.

• Nuclear Engineering and Technology
• /
• v.53 no.7
• /
• pp.2151-2161
• /
• 2021

Nuclear data (ND) sensitivity and uncertainty (S/U) quantification in shielding applications is performed using deterministic and probabilistic approaches. In this paper the validation of the newly developed deterministic program package ASUSD (ADVANTG + SUSD3D) is presented. ASUSD was developed with the aim of automating the process of ND S/U while retaining the computational efficiency of the deterministic approach to ND S/U analysis. The paper includes a detailed description of each of the programs contained within ASUSD, the computational workflow and validation results. ASUSD was validated on two shielding benchmark experiments from the Shielding Integral Benchmark Archive and Database (SINBAD) - the fission relevant ASPIS Iron 88 experiment and the fusion relevant Frascati Neutron Generator (FNG) Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) mock-up experiment. The validation process was performed in two stages. Firstly, the Denovo discrete ordinates transport solver was validated as a standalone solver. Secondly, the ASUSD program package as a whole was validated as a ND S/U analysis tool. Both stages of the validation process yielded excellent results, with a maximum difference of 17% in final uncertainties due to ND between ASUSD and the stochastic ND S/U approach. Based on these results, ASUSD has proven to be a user friendly and computationally efficient tool for deterministic ND S/U analysis of shielding geometries.