• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4367-4381
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• 2023

Nuclear power plants are increasingly being equipped with digital I&C systems. Although some probabilistic safety assessment (PSA) models for the digital I&C of nuclear power plants have been constructed, there is currently no specific internationally agreed guidance for their modeling. This paper presents an initiative by the OECD Nuclear Energy Agency called "Digital I&C PSA - Comparative application of DIGital I&C Modelling Approaches for PSA (DIGMAP)", which aimed to advance the field towards practical and defendable modeling principles. The task, carried out in 2017-2021, used a simplified description of a plant focusing on the digital I&C systems important to safety, for which the participating organizations independently developed their own PSA models. Through comparison of the PSA models, sensitivity analyses as well as observations throughout the whole activity, both qualitative and quantitative lessons were learned. These include insights on failure behavior of digital I&C systems, experience from models with different levels of abstraction, benefits from benchmarking as well as major contributors to the core damage frequency and those with minor effect. The study also highlighted the challenges with modeling of large common cause component groups and the difficulties associated with estimation of key software and common cause failure parameters.

• Membrane and Water Treatment
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• 제14권2호
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• pp.65-76
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• 2023

Given the limited water resources and the presence of multiple decision makers with different and usually conflicting objectives in the exploitation of water resources systems, especially dam's reservoirs; therefore, the decision to determine the optimal allocation of reservoir water among decision-makers and stakeholders is a difficult task. In this study, by combining a fuzzy VIKOR technique or fuzzy multi-criteria decision making (FMCDM) and the Young's bilateral bargaining model, a new method was developed to determine the optimal quantitative and qualitative water allocation of dam's reservoir water with the aim of increasing the utility of decision makers and stakeholders and reducing the conflicts among them. In this study, by identifying the stakeholders involved in the exploitation of the dam reservoir and determining their utility, the optimal points on trade-off curve with quantitative and qualitative objectives presented by Mojarabi et al. (2019) were ranked based on the quantitative and qualitative criteria, and economic, social and environmental factors using the fuzzy VIKOR technique. In the proposed method, the weights of the criteria were determined by each decision maker using the entropy method. The results of a fuzzy decision-making method demonstrated that the Young's bilateral bargaining model was developed to determine the point agreed between the decisions makers on the trade-off curve. In the proposed method, (a) the opinions of decision makers and stakeholders were considered according to different criteria in the exploitation of the dam reservoir, (b) because the decision makers considered the different factors in addition to quantitative and qualitative criteria, they were willing to participate in bargaining and reconsider their ideals, (c) due to the use of a fuzzy-logic based decision-making approach and considering different criteria, the utility of all decision makers was close to each other and the scope of bargaining became smaller, leading to an increase in the possibility of reaching an agreement in a shorter time period using game theory and (d) all qualitative judgments without considering explicitness of the decision makers were applied to the model using the fuzzy logic. The results of using the proposed method for the optimal exploitation of Iran's 15-Khordad dam reservoir over a 30-year period (1968-1997) showed the possibility of the agreement on the water allocation of the monthly total dissolved solids (TDS)=1,490 mg/L considering the different factors based on the opinions of decision makers and reducing conflicts among them.

• 한국융합학회논문지
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• 제7권6호
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• pp.237-247
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• 2016

본 연구는 ISMS인증 취득 후 기업의 성과를 측정하여 기업에게 어떤 영향을 미치는지를 정량적으로 분석하였다. 본 연구에서는 사건연구방법론을 사용하였으며, 기업성과 중에서 기업의 가치에 대한 변화를 측정하기 위해 주가 정보를 활용하여 특정한 사건이 기업의 가치에 미치는 영향에 대해 초과수익률을 통해 분석하였다. ISMS 인증을 취득한 기업을 대상으로 ISMS 인증 취득 후에 초과수익률이 발생한 정도에 대한 분석을 시도하였으며, 나아가 초과수익률을 3가지 상태인 증가, 유지, 감소로 분류하였으며, 집단별로 군집분석을 하였다. 본 연구의 결과는 ISMS 인증 성과에 대한 정량적 측정이 가능할 수 있고, 이를 통해 정보 보호에 대한 체계적인 활동을 요구할 수 있으며, 나아가 기업의 정보보호 활동을 하는데 있어 도움이 될 것으로 기대한다.

• International Journal of Railway
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• 제6권2호
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• 대한간호학회지
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• 제52권4호
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• pp.391-406
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• 2022

Purpose: The purpose of this study was to provide foundational knowledge on nursing tasks performed on patients with COVID-19 in a nationally-designated inpatient treatment unit. Methods: This study employs both quantitative and qualitative approaches. The quantitative method investigated the content and frequency of nursing tasks for 460 patients (age ≥ 18 y, 57.4% men) from January 20, 2020, to September 30, 2021, by analyzing hospital information system records. Qualitative data were collected via focus group interviews. The study involved interviews with three focus groups comprising 18 nurses overall to assess their experiences and perspectives on nursing care during the pandemic from February 3, 2022, to February 15, 2022. The data were examined with thematic analysis. Results: Overall, 49 different areas of nursing tasks (n = 130,687) were identified based on the Korean Patient Classification System for nurses during the study period. Among the performed tasks, monitoring of oxygen saturation and measuring of vital signs were considered high-priority. From the focus group interview, three main themes and eleven sub-themes were generated. The three main themes are "Experiencing eventfulness in isolated settings," "All-around player," and "Reflections for solutions." Conclusion: During the COVID-19 pandemic, it is imperative to ensure adequate staffing levels, compensation, and educational support for nurses. The study further propose improving guidelines for emerging infectious diseases and patient classification systems to improve the overall quality of patient care.

• 대한의용생체공학회:의공학회지
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• 제43권4호
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• pp.241-250
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• 2022

It is known that chronic pain and injury of upper limb joint tissue in manual wheelchair users is usually caused by muscle imbalance, and the propulsion speed is reported to increase this muscle imbalance. In this study, kinematic variables, electromyography, and ultrasonographic images of the upper limb were measured and analyzed at two different propulsion speeds to provide a quantitative basis for the risk of upper extremity joint injury. Eleven patients with spinal cord injury for the experimental group (G_E) and 27 healthy adults for the control group (G_C) participated in this study. Joint angles and electromyography were measured while subjects performed self-selected comfortable and fast-speed wheelchair propulsion. Ultrasound images were recorded before and after each propulsion task to measure the acromiohumeral distance (AHD). The range of motion of the shoulder (14.35 deg in G_E; 20.24 deg in G_C) and elbow (5.25 deg in G_E; 2.57 deg in G_C) joints were significantly decreased (p<0.001). Muscle activation levels of the anterior deltoid, posterior deltoid, biceps brachii, and triceps brachii increased at fast propulsion. Specifically, triceps brachii showed a significant increase in muscle activation at fast propulsion. AHD decreased at fast propulsion. Moreover, the AHD of G_E was already narrowed by about 60% compared to the G_C from the pre-tests. Increased load on wheelchair propulsion, such as fast propulsion, is considered to cause upper limb joint impingement and soft tissue injury due to overuse of the extensor muscles in a narrow joint space. It is expected that the results of this study can be a quantitative and objective basis for training and rehabilitation for manual wheelchair users to prevent joint pain and damage.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권5호
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• pp.13-22
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• 2017

Accurate assessment of agricultural groundwater usage is an essential task to cope with drought that occurs irregularly in time and location. In this study, the agricultural groundwater usage was calculated in nationwide public wells (1,386 bedrock wells) during 5-year period (2010-2014) by using electric power consumption and well specification data. National average of agricultural groundwater usage per each well was estimated as $66.2m^3/day$, corresponding to 21.6% of total permitted volume of groundwater in each well. Chungcheong Nam-do had the highest usage with 38-55.6%. The value increased to 58.1% when the total permitted volume was based upon the supply standard against drought, and the value reached 100% in Chungcheong Nam-do. In Ganghwa distirct that suffered from severe drought in recent years, the average groundwater usage was 61.4%. In 2014, when the drought was the most severe with 45% precipitation of the average annual rainfall, the nationwide usage was turned out to be 25.6%, indicating about 4% higher than average agricultural groundwater usage 21.6%. Therefore, the quantitative assessment of groundwater usage in this study signifies that adequate use of groundwater is crucial to cope with agricultural drought.

• 한국전문물리치료학회지
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• 제25권2호
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• pp.71-77
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• 2018

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.

• 한국IT서비스학회지
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• 제15권3호
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• pp.223-245
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• 2016

This study defines copyrighted public records in broad sense including open government data and public domain except for some private records. Additionally, this study aims to investigate improvement plan for maximizing utilization of copyrighted public records in web-sites using customer side, without consideration of supplier side. For this purpose, qualitative study method was used with grounded theory on analyzed problems from literature review and case study. Literature review was concentrated on definition of open data and abroad utilization indicators whereas case study analyzed current situation of four web-sites providing copyrighted public records. Converged opinions from in-depth interview and various statistical data was analyzed as a basis for grounded theory, then a paradigm model was constructed and future improvement plans were presented. The findings imply that opening of copyrighted public records is not just important for quantitative results, rather it requires qualitative improvement providing latest credible information that is consistent with the demand of the customer. Thus, development of service platform and business models for copyrighted public records are urgent task.

• 감성과학
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• 제4권1호
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• pp.53-60
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• 2001

As a part of HMS(Human-Machine System), the car is very important thing in common life. It is also a significant part to study on the controllers of car that is intentively related with all sensibilities during driving. There are lots of controllers on seating buck of the car. However, there are few study on the sensibility analysis of them. Most of all, the foot controller could be easily overlooked because it could be invisible. This study was based on relationship that the controllers fitted to the driving posture in the drivers' sensibility difference of two transmission modes, automatic and manual transmission. The results show the driver's preference driving posture and sensibility in two kinds of transmission cars. Consequently, it should be designed the seating buck for two different types respectively to be taken comfort driving posture and improve the safety for drivers. Also, it could reduce the fatigue and discomfort in the task of driving. The design of the controllers strongly effects on the drivers' response time. hereby this study was accessed to the sensibility of Korean with analyzing the relationship, quantitative data, and sensibility difference between two kinds of transmission cars.