• Nuclear Engineering and Technology
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• 제29권2호
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• pp.110-126
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• 1997

A two-dimensional continuum model for the hydrogen mining phenomena in the containment subcompartment under severe accident conditions has been developed to predict the spatial distribution of the hydrogen concentration. The model can predict the distribution of time-dependent hydrogen concentration for HEDL experiments well. For the simulation of these experiments, the hydrogen is mixed uniform within the test compartment. To predict the extent of non-uniform distribution, the dominant factors such as the geometrical shape of obstacle and velocity of source injection in mixing phenomena are investigated. If the obstacle disturbing the flow of gas mixture exists in the compartment, the uniform distribution of hydrogen might be not guaranteed. The convective circulation of gas flow is separately formed up and down of the obstacle position, which makes a difference of hydrogen concentration between the upper and lower region of the compartment. The recirculation flow must have a considerable mass flow rate relative to velocity of the source injection to sustain the well-mixed conditions of hydrogen. Finally, in order to account for non-uniform distribution of the hydrogen due to the geometrical configuration the maximum-to-average ratio is functionalized.

• 제어로봇시스템학회논문지
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• 제13권12호
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• pp.1230-1242
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• 2007

This paper describes an IIR/FIR fusion filter for a nonlinear system, and analyzes the stability of the fusion filter. The fusion filter is applied to INS/GPS integrated system, and the performance is verified by simulation and experiment. In the fusion filter, an IIR-type filter (SPKF) and FIR-type filter (MRHKF filter) are processed independently, then the two filters are merged using the mixing probability calculated using the residuals and residual covariance information of the two filters. The merits of the SPKF and the MRHKF filter are embossed and the demerits of the filters are diminished via the filter fusion. Consequently, the proposed fusion filter has robustness against to model uncertainty, temporary disturbing noise, large initial estimation error, etc. The stability of the fusion filter is verified by showing the closeness of the states of the two sub filters in the mixing/redistribution process and the upper bound of the error covariance matrices. This fusion filter is applied into INS/GPS integrated system, and important factors for filter processing are presented. The performance of the INS/GPS integrated system designed using the fusion filter is verified by simulation under various error environments and is confirmed by experiment.

• 동아시아경상학회지
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• 제9권4호
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• pp.17-28
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• 2021

Purpose - This article aims to explore the mechanism in which environmental regulations have positive effects on corporate competitiveness through technological innovation. This study also attempts to examine the relationship between environmental regulation and corporate competitiveness from a technological innovation perspective and explore a desirable relationship between those two. Research design, data, and methodology - Discourse analysis and SWOT analysis is used in terms of methodology, and this study is based on literature review theoretically. The methodology is employed in various ways to describe a variety of environmental issues. Result - The results support that technological innovation is able to play a role in coordinating relationship between environmental regulations and corporate competitiveness. The uncertainty and time lag problems innate to technological innovation function as disturbing factors for individual companies to actively increase R&D investment in response to environmental regulations. Environmental regulations may be considered to be working as a factor consolidating corporate competitiveness through technological innovation to respond to the environmental regulations including climate change issue. Conclusion - This study proposes that to achieve two goals of environmental protection and corporate competitiveness consolidation, policy support from various aspects is implied to be required. This implies that environmental regulations and technical innovation must be harmoniously balanced for future corporate success.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.37-51
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• 2014

In this study, we propose a scheme for providing the consumer of Korea and China with more effective information about the safety of the food to understand easily. Among these countries and consumers, we proposed the graphical displays to help you understand the factors disturbing to think of pesticide residues in common. In the form of a one-dimensional graphical display, whether to provide a safety-related information in the form of conventional foods character, as compared to the graph representation of the larger amounts of information than a two-dimensional character which easily measures the effect of promoting the understanding of the most appropriate information, were reviewed. As a result, in the case of Korea, text and graphs utilizing the standards of pesticide residues than the information provided in a one-dimensional form'Text + Graphics Display'to take advantage of the information provided with the relevant safety standards form the three was found that easy to show. On the other hand, Chinese, between the character and graph form with the advantage that the information providing service type information using the graphic display shown in one dimension could not see the difference between the evaluation and understanding.

• 한국건축친환경설비학회 논문집
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• 제12권6호
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• pp.641-654
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• 2018

Elevator noise in apartment houses is one of the factors which prevent the residents from quiet and comfortable life. The elevator noise measurement method [KS F ISO 16032] is introduced from the matching ISO standard, however, it has problems in the application to the actual measurement. To visualize the problems, measurements in an apartment house are conducted, which has been suffering from the elevator noise for a long time. The measurement itself is extremely difficult due to the low sound pressure level of elevator, which is lower than 35 dB (A), and the even higher background noise level. However the vibration levels measured at the same time are relatively less disturbing As a result of vibration measurement, it was found that the vibration is clearly measured on the wall, and presents a high correlation coefficient of over 0.8 with the noise levels measured This shows that the vibration level measured on the elevator walls may be rather reliable numbers than the elevator noise levels in the actual noisy condition of elevator halls and the vicinity.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.441-456
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• 2022

Shiga toxins (Stxs) are major virulence factors from the enterohemorrhagic Escherichia coli (EHEC), a subset of Stx-producing Escherichia coli. Stxs are multi-functional, ribosome-inactivating proteins that underpin the development of hemolytic uremic syndrome (HUS) and central nervous system (CNS) damage. Currently, therapeutic options for the treatment of diseases caused by Stxs are limited and unsatisfactory. Furthermore, the pathophysiological mechanisms underpinning toxin-induced inflammation remain unclear. Numerous works have demonstrated that the various host ribotoxic stress-induced targets including p38 mitogen-activated protein kinase, its downstream substrate Mitogen-activated protein kinase-activated protein kinase 2, and apoptotic signaling via ER-stress sensors are activated in many different susceptible cell types following the regular retrograde transportation of the Stxs, eventually leading to disturbing intercellular communication. Therapeutic options targeting host cellular pathways induced by Stxs may represent a promising strategy for intervention in Stx-mediated acute renal dysfunction, retinal damage, and CNS damage. This review aims at fostering an in-depth understanding of EHEC Stxs-mediated pathogenesis through the toxin-host interactions.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.809-815
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• 2020

A number of investigations and studies have been conducted in various fields regarding the sediment disasters of Mt. Woomyeon that occurred in July 2011. We collected and compared the topographic information of the general points where debris flows did not occur and the collapse points where the debris flow occurred in order to find out the characteristics of the collapse points in Woomyeon mountain. The collected topographic information is altitude, curvature, slope, aspect and TPI(topographic position index). As a result of comparison, there were relatively many collapse points at an altitude of 210m to 250m, and at a slope of 30° to 40°. In addition, the risk of collapse was low in a cell where the curvature was close to 0, and the risk was higher in concave terrain than in convex terrain. In the case of TPI, there was no statistical difference between the general points and the collapse points when the analysis radius was larger than 200m, and there was a correlation with the curvature when the analysis radius was smaller than 50m. In the case of debris flows that are affected by artificial structures or facilities, there is a possibility of disturbing the topographic analysis results. Therefore, if a research on debris flow is conducted on a mountain area that is heavily exposed to human activities, such as Woomyeon mountain, diversified factors must be considered to account for this impact.

• 한국지역사회생활과학회지
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• 제20권2호
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• pp.263-274
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• 2009

The objective of this study is to verify work satisfaction of school food-service employee, of their job characteristics. Subjects were comprised 9 elementary schools, 11 middle schools, and 3 high schools in Ansan city. Data were analyzed 203 questionnaires for frequency, means, one-way ANOVA, $Scheff{\acute{e}}$ test, t-test, and Pearson correlation using SPSS PC Package. Most of the respondents were high school graduate(91.1%), under one million won salary(41.9%), and non license holder(60.6%). Working conditions were part-time job(41.9%), unlimited contractors(51.2%), and 3-5 years of working experience(21.7%). Measure of overall job satisfaction by Likert-type 5 scale, satisfaction of work operation attitude was 3.55 points and work characteristic duty of 4.32 points. The certificate qualified and elementary school's working posture were more satisfied their work attitude than other groups(p<0.05). Salary satisfaction score showed 2.64 points, but the work esteem satisfaction showed 3.34 points. The factor of working circumstance and potentiality satisfaction was only 2.61 points, but interpersonal connection and communication satisfaction was 3.50 points. Between job satisfactions factors, they were highly correlated with each other. The pride and characteristic duty of the work showed the strongest correlated(p<0.001). The satisfaction score of work operation attitude were significantly correlated with characteristic duty(p<0.001), work esteem, interpersonal relationships and communication(p<0.01). With this results, work satisfaction of food service employees showed a relatively high to perform a job task characteristics and work attitudes. However, the working environment and growth in salaries satisfaction were low. A set of duties must be paid according to the labor intensity. As removing the disturbing factors, the improvement in the quality of the feed will be able to expect substantial effects.

• 한국수정란이식학회지
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• 제28권1호
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• pp.1-6
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• 2013

A lot of works have been dedicated to clarify the reasons why the establishment of embryonic stem cells (ESCs) from pig is more difficult than that from mouse and human. Several concomitant factors such as culture condition including feeder layer, sensitivity of cell to cell contact, definitive markers of pluripotency for evaluation of the validity and optimal timing of derivation have been suggested as the disturbing factors in the establishment of porcine ESCs Traditionally, attempts to derive stem cells from porcine embryos have depend on protocols established for mouse ESCs using inner cell mass (ICM) for the isolation and culture. And more recently, protocols used for primate ESCs were also applied. However, there is no report for the establishment of porcine ESCs. Indeed, ungulate species including pigs have crucial developmental differences unlike rodents and primates. Here we will review recent studies about issues for establishment of porcine ESCs and discuss the promise and strategies focusing on the timing for derivation and pluripotent state of porcine ESCs.

• 디지털융복합연구
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• 제18권9호
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• pp.159-167
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• 2020

본 연구는 경영자가 합리적인 의사결정을 할 때 경영자의 직무스트레스가 의사결정품질에 어떠한 영향을 미치는 지를 알아보고, 기업네트워크와 흡수역량을 통해 의사결정품질을 높일 수 있는지에 대해 실증분석 하고자 하였다. 이를 위해 중소기업 경영자를 대상으로 356명의 설문 데이터를 수집하였고, SPSS v.25와 AMOS v.24를 활용하여 분석하였다. 연구결과 직무스트레스 중 도전적스트레스는 의사결정품질에 정(+)의 영향을 주었고, 방해적스트레스는 의사결정품질에 부(-)의 영향을 주었으며, 기업네트워크와 흡수역량은 모두 의사결정품질에 정(+)의 영향을 주었다. 또한, 도전적스트레스와 방해적스트레스는 기업네트워크와 흡수역량을 통해 의사결정품질에 정(+)의 영향을 주는 것으로 나타났다. 이와 같은 연구결과를 통해 직무스트레스의 도전요인이 의사결정품질에 긍정적 영향을 주는 것을 검증하였으며, 기업네트워크와 흡수역량이 의사결정품질을 높이는 중요한 요인임을 확인할 수 있었다. 이와같이 결론을 논의하고 시사점 및 후속연구의 방향을 제시하였다.