• Journal of Korean Critical Care Nursing
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• v.13 no.3
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• pp.75-85
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• 2020

Purpose : This study aimed to identify the prevalence and risk factors of cognitive impairment in survivors discharged from the intensive care unit (ICU). Methods : This secondary analysis study utilized data from a multicenter prospective cohort of post-ICU patients. We analyzed the data of 175 patients enrolled in the primary cohort who completed the cognitive function evaluation three months after ICU discharge. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) scale. The cut-off points for cognitive impairment were < 23 for face-to-face evaluation and < 18 for telephone evaluation. Results : The prevalence of cognitive impairment three months after ICU discharge was 32.6%. Significant risk factors for cognitive impairment were age ≥ 60 years (OR=10.52, 95% CI=3.65~30.33, p<.001), education < high school graduation (OR=2.53, 95% CI=1.07~6.01, p=.035), unplanned ICU admission (OR=4.01, 95% CI=1.45-11.14, p=.008), and delirium in the ICU (OR=4.33, 95% CI=1.08-17.23, p=.038). Conclusion : ICU nurses should use preemptive strategies to reduce post-ICU cognitive impairment of patients with risk factors. It is necessary to frequently assess and detect early delirium in critically ill patients, while attempting various non-pharmacological interventions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2040-2050
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• 2007

In this study, we present a novel method for estimating the information of MU(motor unit) which is the basic element of human muscle by using surface EMG. Some of the method developed in this field could only estimate the numbers of MU that is activated. However, in our study the MU-simulator based on the line source model was designed to estimate the MU information including the numbers of MU and muscle fiber, conduction velocity, MU diameter, fiber diameter, and end plate position. The SMUAP(single motor unit action potential) detector was designed and CMAP(compound muscle action potential) by electrical stimulus was recorded. With these data, the MU-simulator can estimate the MU information by varying muscle paramater settings through MSE(mean square error) method. Our results shows that the proposed method can be comparable with the method of anatomical studies. Moreover, our system can be utilized to build a tool for diagnosis and treatment assessment of neuromuscular patients.

• Journal of computational fluids engineering
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• v.14 no.2
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• pp.59-67
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• 2009

An accurate prediction of the bypass flow is of great importance in the VHTR core design concerning the fuel thermal margin. Nevertheless, there has not been much effort in evaluating the amount and the distribution of the core bypass flow. In order to evaluate the behavior and the distribution of the coolant flow, a unit-cell experiment was carried out. Unit-cell is the regular triangular section which is formed by connecting the centers of three hexagonal blocks. Various conditions such as the inlet mass flow rate, block combinations and the size of bypass gap were examined in the experiment. CFD analysis was carried out to analyze detailed characteristics of the flow distribution. Commercial CFD code FLUENT 6.3 was validated by comparing with the experimental results. In addition, SST model and standard k-$\varepsilon$ model were validated. The results of CFD simulation show good agreements with the experimental results. SST model shows better agreement than standard k-$\varepsilon$ model. Results showed that block combinations and the size of the bypass gap have an influence on the bypass flow ratio but the inlet mass flow rate does not.

• Journal of Information Science Theory and Practice
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• v.11 no.2
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• pp.37-66
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• 2023

Scientometrics and research evaluation describe and analyze research publications when conducting publication, citation, and topic analyses. However, what exactly is a (scientific, academic, scholarly or research) publication? This article demonstrates that there are many problems when it comes to looking in detail at quantitative publication analyses, citation analyses, altmetric analyses, and topic analyses. When is a document a publication and when is it not? We discuss authorship and contribution, formally and informally published documents, as well as documents in between (preprints, research data) and the characteristics of references, citations, and topics. What is a research publication? Is there a commonly accepted criterion for distinguishing between research and non-research? How complete and unbiased are data sources for research publications and sources for altmetrics? What is one research publication? What is the unit of a publication that causes us to count it as "1?" In this regard, we report problems related to multi-author publications and their counting, weighted document types, the unit and weighting of citations and references, the unit of topics, and counting problems-not only at the article and individual researcher level (micro-level), but also at the meso-level (e.g., institutions) and macro-level (e.g., countries). Our results suggest that scientometric counting units are not reliable and clear. Many scientometric and research evaluation studies must therefore be used with the utmost caution.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1365-1381
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• 2023

In this paper, a procedure for evaluating the structural integrity of the PCSG (Printed Circuit Steam Generator) unit block is presented with a simplified FE (finite element) analysis technique by applying the homogenization method. The homogenization method converts an inhomogeneous elastic body into a homogeneous elastic body with same mechanical behaviour. This method is effective when the inhomogeneous elastic body has repetitive microstructures, and thus the method was applied to the sheet assembly among the PCSG unit block components. From the method, the homogenized equivalent elastic constants of the sheet assembly were derived. The validity of the determined material properties was verified by comparing the mechanical behaviour with the reference model. Thermo-mechanical analysis was then performed to evaluate the structural integrity of the PCSG unit block, and it was found that the contact region between the steam header and the sheet assembly is a critical point where large bending stress occurs due to the temperature difference.

• Journal of Soil and Groundwater Environment
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• v.25 no.3
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• pp.65-73
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• 2020

Exposure assessment methodology for outdoor air inhalation pathways (i.e., inhalation of volatile compounds and fugitive dust in outdoor air) was investigated. Default values of several parameters currently used in Korea (e.g., Q/C; inverse value of concentration per unit flux, and frs; soil fraction in PM10) may not be suitable and lack site-specificity, as they have been adopted from the risk assessment guidance of the United States or the Netherlands. Such limitation can be addressed to a certain degree by incorporating the volatilization factor (VF) and the particulate emission factor (PEF) with Box model. This approach was applied to an exposure assessment of a site contaminated with petroleum hydrocarbons in Korea. The result indicated that the suggested methodology led to more accurate site-specific exposure assessment for outdoor inhalation pathways. Further work to establish methodology to determine site-specific Q/C values in Korea needs to be done to secure the reliability of the exposure assessment for outdoor air inhalation pathways.

• KIEAE Journal
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• v.13 no.4
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• pp.11-19
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• 2013

The purpose of this study is to establish the assessment baseline of $CO_2$ emissions from building operations in the view of GHG reduction policy in Korea. The assessment baseline of $CO_2$ emissions shall be used in GHG policy and Carbon Credits in building sectors, but the assessment baseline has not been studied enough or established yet. Also, $CO_2$ emissions from building operations will be variable according to the building occupancy. Therefore the baseline will be different and this study aimed at the establishment of the assessment baseline for residential apartments and office buildings firstly. After reviews of BEER and international standards for building $CO_2$ emissions such as ISO and UNEP-SBCI documents, the analysis of BEER certification data has been pursued for 292 residential apartment complexes and 65 office buildings in South Korea during 2004~2012. As analysis results, the assessment baseline was set to 23.03 $kg{\cdot}CO_2/m^2{\cdot}yr$ or 1.95 $t{\cdot}CO_2/unit{\cdot}yr$ for residential apartment complexes, and 95.91 $kg{\cdot}CO_2/m^2{\cdot}yr$ for office buildings according to the BEER certification basis. Additional assessment baselines were calculated according to year basis, region basis, public and private basis, and GHG policy basis. Finally, the established baseline for residential apartment complexes has been applied for the pilot project in M district, Seoul, and showed 24.97% reduction rate according to the BEER certification basis.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.71-79
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• 2007

Land suitability assessment has been enforced by the National Land Planning and Utilization Act since 2003 to prevent urban sprawl and protect natural environment. It assesses developmental, agricultural or preservable suitability of land parcel according to such criteria as soil, location and usability by local governments. Land suitability assessment system (LSAS) has been introduced to prevent cursory development by urban sprawl and to lead a harmonious development with conservation in the non-urban area. However, with the lack of experience and knowledge various problems have been arisen in the operation of this system, raising a question for the improvement of the assessment unit of land. The purpose of this study is to investigate methods of developing land assessment as a sustainable land use management tool. In this study, land suitability assessment has been executed through geographic information systems. On the basis oh the results of analysis, practical and institutional problems are described, and technical and institutional solutions are suggested.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.562-571
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• 2000

Practical research, as well as theoretical research, about performance assessment is important for the successful application of performance assessment in school. To do this, two school teachers with professional educators studied theoretical basics of performance assessment for several months. As a result, 4 categories of issues for designing performance assessment were generated and described by teachers. Based on those issues, 5 directions for development were established, and finally, 7 types of performance assessment were developed. Developed items were disseminated to other two middle school teachers for application in school. After application during several months, interviews with them were conducted to obtain the informations and implications about the practical application of performance assessment.

• Journal of Korean Society of societal Security
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• v.1 no.1
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• pp.63-67
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• 2008

This study focuses on assessing the security ri sk or the terrorism in chemical process industries. This research modifies conventional method for assessing the terrorism risk. The risk assessment method is developed and it is implemented as software to analyze the possibility of terrorism and sabotage. This program includes five steps; asset characterization, threat assessment, vulnerability analysis, risk assessment and new countermeasures. It is a systematic, risk based approach in which risk is a function of the severity of consequences of an undesired event, the likelihood of adversary attack, and the likelihood of adversary success in causing the undesired event. The reliability of the program is verified using a dock zone case. The case dock zone includes a storage farm, a manufacturing plant, an electrical supply utility, a hydrotreater unit, many containers, and administration buildings. This study represents chemical terrorism response technology, the prevention plan, and new countermeasure to mitigate by using risk assessment methods in the chemical industry and public sector. This study suggests an effective approach to the chemical terrorism response management.