• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.138-145
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• 2019

With the application of digital technology to safety-critical infrastructures, cyber-attacks have emerged as one of the new dangerous threats. In safety-critical infrastructures such as a nuclear power plant (NPP), a cyber-attack could have serious consequences by initiating dangerous events or rendering important safety systems unavailable. Since a cyber-attack is conducted intentionally, numerous possible cases should be considered for developing a cyber security system, such as the attack paths, methods, and potential target systems. Therefore, prior to developing a risk-informed cyber security strategy, the importance of cyber-attacks and significant critical digital assets (CDAs) should be analyzed. In this work, an importance analysis method for cyber-attacks on an NPP was proposed using the probabilistic safety assessment (PSA) method. To develop an importance analysis framework for cyber-attacks, possible cyber-attacks were identified with failure modes, and a PSA model for cyber-attacks was developed. For case studies, the quantitative evaluations of cyber-attack scenarios were performed using the proposed method. By using quantitative importance of cyber-attacks and identifying significant CDAs that must be defended against cyber-attacks, it is possible to develop an efficient and reliable defense strategy against cyber-attacks on NPPs.

• Culinary science and hospitality research
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• v.21 no.2
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• pp.1-10
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• 2015

The purpose of this study was to establish the critical limit of CCP (Critical Control Point) of a HACCP (Hazard Analysis Critical Control Point) system used in the production of seasoned laver products. The hazard analysis examined microbial evaluations and developed a HACCP management plan for the heating process. The results were determined to be capable of reducing the biological element of CCP via the secondary roasting process. This study examined general bacteria and pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, and Bacillus cereus at temperatures ranging from $170^{\circ}C$ to $230^{\circ}C$ and for 3.0 to 5.5 seconds at a time. Before the secondary roasting process, pathogenic microorganisms were all negative, although the presence of general bacteria was still detected. General bacteria was reduced to $1.0{\times}10CFU/g$ after the temperature was set at $230^{\circ}C$ for a period of 5.5 seconds. In conclusion, it suggested that a HACCP plan was necessary for management standard and systematic approach in the establishment of critical limit, problem resolution, verification method, education, and records management through a secondary roasting process.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.65-70
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• 2000

It is blown that the loudness is one of the most important metrics in assessing the sound quality and a calculation method for loudness has been standardized for steady sounds. In this study, a new loudness model is suggested for dealing with the transient sound for a unified analysis of various practical sounds. A signal processing technique is introduced for this purpose, which is required for the band subdivision and the prediction of band-level change of transient sounds. In addition, models for the post-masking and the temporal integration are adopted in the analysis of the loudness of transient sounds. In order to solve the problem of the conventional loudness model in the pure-tone signal processing, a critical band filter is employed in the analysis, which consists of 47 critical filters having a filter spacing of a half of the critical bandwidth. For testing the effectiveness of the present model, the predicted responses are compared with the experimental data and it is observed that they are in good agreements.

• Journal of Korean Clinical Nursing Research
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• v.27 no.3
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• pp.279-293
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• 2021

Purpose: The purpose of this study was to develop a Korean nursing work environment scale for critical care nurses (KNWES-CCN) and verify its validity and reliability. Methods: A total of 46 preliminary items were selected using content validity analysis of experts on 64 candidate items derived through literature reviews and in-depth interviews with critical care nurses. 535 critical care nurses from 21 hospitals responded to the preliminary questionnaire from February to March 2021. The collected data were analysed using construct, convergent and discriminant validities, and internal consistency and test-retest reliability. Results: The 23 items in 4 factors accounted for 55.6% of the total variance were identified through item analysis and exploratory factor analysis (EFA). EFA was performed with maximum likelihood method including direct oblimin method. In the confirmatory factor analysis, KNWES-CCN consisted of 21 items in 4 factors by deleting the items that were not meet the condition that the factor loading over .50 or the squared multiple correlation over .30. This model was considered to be suitable because it satisfied the fit index and acceptable criteria of the model [𝒳²=440.47 (p<.001), CMIN/DF=2.41, GFI=.86, SRMR=.06, RMSEA=.07, TLI=.90, CFI=.91]. The item total correlation values ranged form .32 to .73 and its internal consistency was Cronbach's α=.92. The reliability of the test-retest correlation coefficient was .72 and the intra-class correlation coefficient was .83. Conclusion: The KNWES-CCN showed good validity and reliability. Therefore, it is expected that the use of this scale would measure and improve nursing work environment for critical care nurses in Korea.

• Journal of Korean Academy of Nursing
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• v.35 no.2
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• pp.382-389
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• 2005

Purpose: This longitudinal study was done to investigate critical thinking dispositions and critical thinking skills of nursing students enrolled in a 4-year baccalaureate program at a university in Korea. Method: The study used a longitudinal design. A convenience sample of 32 nursing students who were completing their 1st, 2nd, 3rd, and 4th year in a baccalaureate program at a selected university was included. The subjects completed the California Critical Thinking Dispositions Inventory (CCTDI), the California Critical Thinking Skill Test (CCTST), and a demographic questionnaire. Data was analyzed by descriptive statistics, repeated ANOVA, adjusted p-values, and Pearson's correlation coefficient with SAS 8.12. Results: There was statistically significant improvement according to academic year in the CCTDI total mean score (F=7.54, p= .0001) and subscales of Open-mindedness, Self-confidence, and Maturity. Contrarily, no statistically significant difference was found in the CCTST total mean score and subscales' score except Analysis. Conclusion: There is no significant correlation between critical thinking dispositions and skills, so it will be necessary to repeat a study like this, and the translated instruments should be modified by considering Korean culture.

• Journal of Korean Critical Care Nursing
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• v.11 no.2
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• pp.1-10
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• 2018

Purpose : This study aimed to develop an in-depth and comprehensive understanding of the experiences of critical care nurses caring for dying patients. Method : Eleven critical care nurses with experience in caring for dying patients were recruited from four tertiary hospitals. Semi-structured face-to-face interviews were conducted between November 2016 and March 2017. The transcribed data were analyzed using qualitative content analysis to identify major themes and sub-themes that represented the experiences of critical care nurses. Results : The following six themes, and twelve sub-themes, were identified: (1) the gap between expectation and reality, (2) a distorted meaning of death, (3) repeated emotional pain and stress, (4) finding a solution alone, (5) sublimation into mission and calling, and (6) integration into one's own life. Conclusion : This study found that critical care nurses experience various psychological difficulties while caring for dying patients, and they made efforts on their own to overcome them. These findings are expected to inform the development of specialized programs to support critical care nurses to tackle these challenges, create guidelines on caring for dying patients, and help promote death education.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.89-109
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• 2013

The study analyzes mission statements of Library and Information Science schools in the United States. It aims to reveal identities of LIS by Critical Discourse Analysis (CDA). The study examines the strategies or stereotypes of academic mission statements in LIS as a genre. Mission statements are analyzed using discourse analysis to find common ideology using agency, modality, and lexical analysis. A comparative analysis of two mission statements is also conducted within discursive practices to reveal characteristics of two schools. This study has value in that it provides implications for other ideological discussions applicable to LIS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.974-979
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• 2008

A design process for the structure-borne noise in a passenger vehicle is presented. The proposed process is improved from the previous one. The major difference between the current and last ones is that most of the countermeasures should be developed before fixing a tool for structural parts. This is requested for QCDP(Quality, Cost, Delivery and Productivity) by the design engineers. The proposed one consists of 4 steps: Problem definition, Cause analysis, Development of counter-measure and Validation. Based on the general rule: divide and conquer, the complex problem can be simplified into a few critical sub-systems through the first step: Problem definition. Secondly, the critical causes can be identified for the critical sub-systems through the second step: Cause analysis. Thirdly, effective countermeasures are investigated and produced through the third step: Countermeasure development. The proposed countermeasures are finally validated in the forth step: Validation.

• Journal of Korean Academy of Nursing Administration
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• v.8 no.1
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• pp.123-135
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• 2002

Purpose: In this study, the critical pathway for laparoscopic cholecystectomy patients was developed and applied for clinical study. The effectiveness of the critical pathway was analyzed. Method: The subjects with no critical pathway services of this study were 30 laparoscopic cholecystectomy operation patients, who were hospitalized in B General Hospital in Busan from Nov. 28. 2000 to May 2. 2001. The subjects with critical pathway services of this study were 30 laparoscopic cholecystectomy operation patients, who were hospitalized in B General Hospital in Busan from June. 11. 2001 to Oct. 31. 2001. Results: 1. Development for critical pathway Preliminary critical pathway for the laparoscopic cholecystectomy patients was developed though analysis of the reference and 34 case of medical record. The items on the y-axis were assessment, test, treatment, diet, fluid, consult, medication, activity and education and the items on the x-axis were till 3days after operation. The developed critical pathway was applied in clinical field. 2.　Effectiveness of application on developed critical pathwayPost operational complication was not found in neither the critical pathway using Group nor Non-using Group. Hospitalization period mean was 4.63 days for the using Group and 5.93 days for the Non-using Group(P=.001). The mean cost for medical examination and treatment for the using Group was 786,270 won, 117,454 won(12.9%) less than that of the Non-using Group, 903,724 won(P=.000). The degree of satisfaction for the using group was 3.7 points, for the Non-using Group, 3.15 points. The degree of satisfaction for the used Group was 0.55 points higher than that for the Non-using Group and there was a statistically significant difference(P=.000). Concousion: From results of this study, Using the critical pathway in the laparoscopic cholecystectomy operational patients was effective in decreasing the hospitalization period and cost, and increasing the satisfaction about the medical service.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.179-189
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• 2003

Gate poly-silicon critical dimension is a prime characteristic of a metal-oxide-semiconductor field effect transistor. It is important to achieve the uniformity of gate poly-silicon critical dimension in order that a semiconductor device has acceptable electrical test characteristics as well as a semiconductor wafer fabrication process has a competitive net-die-per-wafer yield. However, on gate poly-silicon critical dimension, the complexity associated with a semiconductor wafer fabrication process entails hierarchical variance components according to run-to-run, wafer-to-wafer and even die-to-die production unit changes. Specifically, estimates of the hierarchical variance components are required not only for disclosing dominant sources of the variation but also for testing the wafer-level uniformity. In this paper, two experimental designs, a two-stage nested design and a randomized complete block design are considered in order to estimate the hierarchical variance components. Since gate poly-silicon critical dimensions are collected from fixed die positions within wafers, a factor representing die positions can be regarded as fixed in linear statistical models for the designs. In this context, the two-stage nested design also checks the wafer-level uniformity taking all sampled runs into account. In more detail, using variance estimates derived from randomized complete block designs, Duncan's multiple range test examines the wafer-level uniformity for each run. Consequently, a framework presented in this study could provide guidelines to practitioners on estimating the hierarchical variance components and testing the wafer-level uniformity in parallel for any characteristics concerned in semiconductor wafer fabrication processes. Statistical analysis is illustrated for an experimental dataset from a real pilot semiconductor wafer fabrication process.