• Tuberculosis and Respiratory Diseases
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• v.81 no.4
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• pp.330-338
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• 2018

Background: We developed an additional laser guidance system to improve the efficacy and safety of conventional computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB), and we conducted this study to evaluate the efficacy and safety of our system. Methods: We retrospectively analyzed the medical records of 244 patients who underwent CT-guided PTNB using our additional laser guidance system from July 1, 2015, to January 20, 2016. Results: There were nine false-negative results among the 238 total cases. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of our system for diagnosing malignancy were 94.4% (152/161), 100% (77/77), 100% (152/152), 89.5% (77/86), and 96.2% (229/238), respectively. The results of univariate analysis showed that the risk factors for a false-negative result were male sex (p=0.029), a final diagnosis of malignancy (p=0.033), a lesion in the lower lobe (p=0.035), shorter distance from the skin to the target lesion (p=0.003), and shorter distance from the pleura to the target lesion (p=0.006). The overall complication rate was 30.5% (74/243). Pneumothorax, hemoptysis, and hemothorax occurred in 21.8% (53/243), 9.1% (22/243), and 1.6% (4/243) of cases, respectively. Conclusion: The additional laser guidance system might be a highly economical and efficient method to improve the diagnostic efficacy and safety of conventional CT-guided PTNB even if performed by inexperienced pulmonologists.

• Journal of KIISE
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• v.44 no.9
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• pp.893-907
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• 2017

In safety-critical systems, software defects may have serious consequences. Therefore, defects should be considered during the requirements specification process, which is the first step of a software development lifecycle. Stakeholder requirements that are usually written in natural language are difficult to derived, and there may also be defects due to ambiguity and inaccuracy. To address these issues, we propose a requirement specification method using a standardized Boilerplate and a GSN Model. The Boilerplate is a semi-standard language that follows a predefined format. Due to its ability to provide a consistent representation of the requirements, boilerplate helps stakeholders avoid ambiguities about what they mean and to define the exact meaning of the requirement. Meanwhile, GSN is recognized notation to prepare a Safety Case to prove to authorities that a system is safe. It can be expressed as a functional goal, e.g., Safety Evidence, etc. The proposed study allows an analyst to easily identify a fault from the early stage of the software development lifecycle. The Boilerplate and GSN Model are designed to specify the requirements of safety critical systems and to prove safety conformity through a connection with Safety Evidence. In addition, the proposed approach is also useful to develop secure software by correcting deficiencies in the requirements found during this process.

• Journal of Korean Critical Care Nursing
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• v.11 no.3
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• pp.85-94
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• 2018

Purpose : The purpose of this study was to identify the association between safety care activity and documentation of nursing records among nurses working in hospitals and to provide basic data for developing hospital policy for the documentation of nursing records. Methods : By using a self-reported questionnaire, data were collected from 212 nurses working in six general hospitals in Jeju province from November 2015. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and stepwise multiple regression with the SAS WIN 9.2 program. Results : Safety care activity was positively correlated with the documentation of nursing records (r=.83, p<.001). The documentation of nursing records was significantly predicted by safety care activity, working department, and nursing delivery system, and 70.9% of the variance in the documentation of nursing records was explained (F=172.31, p<.001). Conclusions : In this study, safety care activity was the most influencing factor for the documentation of nursing records. Improving work circumstances and building a system are required for nurses' safety care activity to lead to good documentation of nursing records.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.45-53
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• 2019

Thermal-hydraulic passive safety systems (PSSs) are incorporated into many advanced reactor designs on the bases of simplicity, economics and inherent safety nature. Several factors among which are the critical parameters (CPs) that influence failure and reliability of thermal-hydraulic (t-h) passive systems are now being explored. For simplicity, it is assumed in most reliability analyses that the CPs are independent whereas in practice this assumption is not always valid. There is need to critically examine the dependency influence of the CPs on reliability of the t-h passive systems at design stage and in operation to guarantee safety/better performance. In this paper, two multivariate analysis methods (covariance and conditional subjective probability density function) were presented and applied to a simple PSS. The methods followed a generalized procedure for evaluating t-h reliability based on dependency consideration. A passively water-cooled steam generator was used to demonstrate the dependency of the identified key CPs using the methods. The results obtained from the methods are in agreement and justified the need to consider the dependency of CPs in t-h reliability. For dependable t-h reliability, it is advisable to adopt all possible CPs and apply suitable multivariate method in dependency consideration of CPs among other factors.

• International Journal of Quality Innovation
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• v.9 no.1
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• pp.134-152
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• 2008

Almost every country around the world has been focusing on food safety in intense and multifaceted ways. The use of Hazard Analysis Critical Control Points (HACCP) is widely accepted as a food safety management system. This paper investigates the success factors of HACCP practices with reference to the domains of food production, processing and delivery. A literature review of food safety and management articles was conducted. Using the keywords search, the online Emerald Database was used and a total of 102 journal articles were identified between 1994 and 2007. The study examined a list of 20 success factors. Results show that 'food regulations,' 'role of the industry,' 'government policies and interventions,' 'training on food safety and hygiene,' and 'food contamination and/or poisoning' share the spotlight as being the most critical factors for HACCP practices in organisations. Future research could investigate a holistic paradigm that incorporates the success factors and aligns HACCP measures for attaining safety performance goals.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.313-323
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• 2017

As vehicles become more intelligent this is focused on ways to enhance safety and convenience for both drivers and passengers. In particular, x-by-wire systems that replace rigid mechanical components with dynamically configurable electronic elements are being developed to expand intelligent functions, such as adaptive cruise control or lane departure warning system. Because the malfunction of safety-related modules controlling critical functions, such as brakes, throttle, and steering in x-by-wire systems, can cause injury or death, safety and reliability are the most critical issue for automotive vendors and parts manufacturers. In an effort to develop better and effective brake-by-wire system, this paper presents EMB system by using the low speed electric vehicle, which is not required large braking force, with motor controller. In addition, we design performance evaluation system of EMB with 1/4 low speed electric vehicle model and suggested EMB is evaluated through the performance evaluation system.

• 한국항공우주법학회:학술대회논문집
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• 2008.05a
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• pp.165-182
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• 2008

The purpose of this study is to review the changes in the aviation safety management system, how that system has evolved and what forces caused these changes to take place. Also included is an examination of the development process of the aviation safety management system in view of the new institutionalism, identifying the patterns of change. Based on the results of this study, I propose policy methods to design a desirable civil aviation safety system with a view toward raising the safety standards in the Korean civil aviation community. The major analysis variables are as follows: first, aviation accidents caused by external factors and international standards as independent variables; second, environmental changes and political processes affecting aviation safety management system as major mediating variables; and third, the aviation safety management legal system, the aviation safety management organizations and an expert participation system as dependent variables. The institutional changes and continuance of the aviation safety management system show that when specific circumstances arise, the continuance lasts depending on the path dependency, and in a certain circumstance, when immanent changing factors reach a critical point, the system suddenly changes by a punctuated equilibrium, which are all included in this study.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.994-1002
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• 2013

This study suggests a generalized availability and safety evaluation model to evaluate the influences to the system's fault tolerant capabilities depending on automatic fault detection function such as the automatic periodic testings. The conventional evaluation model of automatic fault detection function deals only with the self diagnostics, and supposes that the fault detection coverage of self diagnostics is always constant. But all of the fault detection methods could be degraded. For example, the periodic surveillance test has the potential human errors or test equipment errors, the self diagnostics has the potential degradation of built-in logics, and the automatic periodic testing has the potential degradation of automatic test facilities. The suggested evaluation models have incorporated the loss or erroneous behaviors of the automatic fault detection methods. The availability and the safety of each module of the safety grade platform have been evaluated as they were applied the automatic periodic test methodology and the fault tolerant evaluation models. The availability and safety of the safety grade platform were improved when applied the automatic periodic testing. Especially the fault tolerant capability of the processor module with a weak self-diagnostics and the process parameter input modules were dramatically improved compared to the conventional cases. In addition, as a result of the safety evaluation of the digital reactor protection system, the system safety of the digital parts was improved about 4 times compared to the conventional cases.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.583-588
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• 2016

The high-temperature steam pipes of thermal power plants are subjected to severe conditions such as creep and fatigue due to the power plant frequently being started up and shut down. To prevent critical pipes from serious damage and possible failure, inspection methods such as computational analysis and online piping displacement monitoring have been developed. However, these methods are limited in that they cannot determine the life consumption rate of a critical pipe precisely. Therefore, we set out to develop a life assessment system, based on a three-dimensional piping displacement monitoring system, which is capable of evaluating the life consumption rate of a critical pipe. This system was installed at the "M" thermal power plant in Malaysia, and was shown to operate well in practice. The results of this study are expected to contribute to the increase safety of piping systems by minimizing stress and extending the actual life of critical piping.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.38
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• pp.61-68
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• 1996

Quality Assurance Principles must be effectively implemented in developments and in use of safety critical software in nuclear industry. Brief definitions related to computer software and quality assurance were defined and several methods for evaluating software quality were proposed herewith. Independent verification and validation was suggested to assure the quality of safety critical software.