• 한국안전학회지
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• 제10권3호
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• pp.56-61
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• 1995

The behaviors of flame propagation and quenching in a pipe were investigated to make a design criteria of flame arrester. The effects of sealing condition of pipe end, pipe diameter and lengh were studied, and also the effects of thickness of ceramic honycomb monolith on the quenching ability were discussed. Experimental results showed that the flame velocity in case of closed pipe was increased about twenty times faster than that of opened and the sealing coditions of pipe end and length showed significant effects on it. The quenching ability of ceramic honycomb monolith was Increased with thickness and coincided well with Palmer's equation.

• 대한의용생체공학회:의공학회지
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• 제15권2호
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• pp.143-150
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• 1994

Wall shear rate or stress is believed to be a major hemodynamic variable influencing atherosclerosis and artery-graft anastomic intimal hyperplasia. The purpose of this study is to verify the effects of radial wall motion, artery-graft compliance and diameter mismatch, and impedance phase angle on the wall shear rate distribution near an end-to-end artery-graft anastomosis model. The results show that radial wall motion of the elastic artery model lowers the mean wall shear rates under pulsatile flow condition by 15 to 20 % comparing to those under steady flow condition at the same mean flow rate. Impedance phase angle seems to have small effects on the mean and amplitude of the wall shear rate distribution. In order to study the effects of compliance and diameter mismatch on the wall shear rates, two models are studied-Model I has 6% and Model I has 6% and Model II has 11% smaller graft diameter. Divergent geometry caused by diameter mismatch near the distal sites reduces the mean wall shear rates significantly, and this low shear region is believed to be prone to intimal hyperplasia.

• Journal of Hospice and Palliative Care
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• 제24권3호
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• pp.144-153
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• 2021

Purpose: Advance care planning (ACP) is widely understood to improve end-of-life care. This systematic review and meta-analysis aimed to examine the effects of ACP interventions on decision conflict and psychological distress. Methods: A search of PubMed, CINAHL, CENTRAL, EMBASE, KISS, KoreaMed, and RISS was conducted in November 2020. The study included randomized controlled trials. Data were pooled using fixed- and random-effects models. Results: Fourteen studies were identified that cumulatively included 1,548 participants. ACP interventions were effective in alleviating decision conflict (d=-0.53; 95% CI: -0.83 to -0.23), depression (d=-1.22; 95% CI: -1.71 to -0.74) and anxiety (d=-0.76; 95% CI: -1.12 to -0.39). Conclusion: ACP interventions have significant positive effects on reducing decision conflict and psychological distress. A high level of bias was shown related to allocation concealment and blinding. The results of this study are expected to be useful for end-of-life care providers to improve the effectiveness of ACP interventions.

• Structural Engineering and Mechanics
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• 제16권3호
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• pp.275-294
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• 2003

In this study, 24 high-strength concrete dapped-end beams were tested to study the effects of the amount of main dapped-end reinforcement, the nominal shear span-to-depth ratio, and the concrete strength on the shear strength of dapped-end beams. Test results indicate that the shear strength of dapped ends increases with the increase in the amount of main dapped-end reinforcement and the concrete strength. The shear strength of dapped-end beam increases with the decrease of nominal shear span-to-depth ratio. A simplified method for determining the shear strength of reinforced concrete dapped ends is also proposed in this paper. The shear strengths predicted by the proposed method and the approach of PCI Design Handbook are compared with test results. The comparison shows that the proposed method can more accurately predict the shear strength of reinforced concrete dapped-end beams than the approach of PCI Design Handbook.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.15-24
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• 2008

The data delivery confirmation method of MIL-STD-188-220C, which is a tactical wireless mobile Ad-Hoc communication protocol, is that a source node requires the end-to-end ack from all destination nodes and the data-link ack from 1-hop neighboring destination nodes and relaying nodes, regardless of the hop distance from a source node to destination nodes. This method has the problem to degrade the whole communication network performance because of excessive data traffic due to the duplicate use of end-to-end ack and data-link ack, and the collision among end-to-end acks on the wireless network in the case of confirming a data delivery within an 1-hop distance. In order to solve this problem, this paper has proposed the method to perform the data delivery confirmation with the improvement of communication network performance through the data traffic reduction by achieving the reliable data delivery confirmation requiring the only data-link ack within an 1-hop distance. The effects of the proposed method are analyzed in the two aspects of the data delivery confirmation delay time and the data delivery confirmation success ratio.

• 대한기계학회논문집A
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• 제33권7호
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• pp.664-672
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• 2009

Nozzle in nuclear power plant is connected to pipe using safe end. Dissimilar metal weld between nozzle and safe end is followed by similar metal weld between safe end and pipe. And thus residual stress in dissimilar metal weld can be affected by similar metal weld. Similar metal weld impose bending stress on dissimilar metal weld, which is according to the length of safe end. In this study, simple nozzle model which covers various radius to thickness ratios was proposed to quantify residual stress in dissimilar metal weld based on finite element analyses. As a result, short length of safe end was proved to be more effective to mitigate residual stress in dissimilar metal weld and critical effective length of safe end is provided according to the radius to thickness ratio.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.228-233
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• 2008

Effects of chaperones on mRNA stability and gene expression were studied in order to develop an efficient Escherichia coli expression system that can maximize gene expression. The stability of mRNA was modulated by introducing various secondary structures at the 5'-end of mRNA. Four vector systems providing different 5'-end structures were constructed, and genes encoding GFPuv and endoxylanase were cloned into the four vector systems. Primer extension assay revealed different mRNA half-lives depending on the 5'-end secondary structures of mRNA. In addition to the stem-loop structure at the 5'-end of mRNA, coexpression of dnaK-dnaJ-grpE or groEL-groES, representative heat-shock genes in E. coli, increased the mRNA stability and the level of gene expression further, even though the degree of stabilization was varied. Our work suggests that some of the heat-shock proteins can function as mRNA stabilizers as well s protein chaperones.

• Safety and Health at Work
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• 제4권3호
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• pp.136-141
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• 2013

Background: Occupational end users of pesticides may experience bodily absorption of the pesticide products they use, risking possible health effects. The purpose of this paper is to provide a guide for researchers, practitioners, and policy makers working in the field of agricultural health or other areas where occupational end use of pesticides and exposure issues are of interest. Methods: This paper characterizes the health effects of pesticide exposure, jobs associated with pesticide use, pesticide-related tasks, absorption of pesticides through the skin, and the use of personal protective equipment (PPE) for reducing exposure. Conclusions: Although international and national efforts to reduce pesticide exposure through regulatory means should continue, it is difficult in the agricultural sector to implement engineering or system controls. It is clear that use of PPE does reduce dermal pesticide exposure but compliance among the majority of occupationally exposed pesticide end users appears to be poor. More research is needed on higher-order controls to reduce pesticide exposure and to understand the reasons for poor compliance with PPE and identify effective training methods.

• Journal of Hospice and Palliative Care
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• 제24권3호
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• pp.154-164
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• 2021

Purpose: The purpose of this study was to examine the effects of a death preparation education program for nurses working in convalescent hospitals on death anxiety, death attitudes, and attitudes toward end-of-life care. Methods: This was a quasi-experimental study with a non-equivalent control group, pre-test and post-test design. Among 53 participants, 26 were assigned to the non-equivalent experimental group and 27 to the control group. The program was performed in the formats of lectures, video-watching, group discussions, and sharing, and consisted of 10 sessions held twice a week, for 5 weeks (90 minutes per session). Data were analyzed using descriptive statistics, the t-test, and the chisquare test in SPSS version 21.0. Results: Significant differences between the experimental and control groups were observed in death anxiety (t=7.62, P<0.001), death attitudes (t=-7.58, P<0.001), and attitudes to end-of-life care (t=-10.30, P<0.001). Conclusion: It was confirmed that the death preparation education program reduced death anxiety and had a positive effect on death attitudes and attitudes toward end-of-life care. Based on the results of this study, it is expected that specialized and systematic education that can increase the implementation and stability of death preparation education in various fields, including nursing, will have a positive effect on both hospice patients and members of society more broadly.

• Journal of Hospice and Palliative Care
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• 제24권3호
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• pp.135-143
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• 2021

End-of-life patients experience physical, mental, social, and existential distress. While medical personnel provide medication and care to alleviate patients' distress, listening to and interacting with patients remains essential for understanding their psychological condition. The most important tool, though difficult to implement in practice, is end-of-life discussion (EOLD). EOLD has been shown to have positive effects on end-of-life treatment choices, achievement of patients' life goals, improvements in the quality of life of patients and their families, and the prevention of depression and complicated grief among bereaved family members. EOLD is not often undertaken in clinical practice, however, due to hesitancy among medical personnel and patients for various reasons. In order to conduct an EOLD, the patient's judgment, psychiatric illnesses such as delirium and depression, and psychological issues such as the side effects of psychotropic drugs, denial, and collusion must be evaluated. Open and honest conversation, treatment goal setting, the doctor's familiarity with the patient's background, and attentiveness when providing information are important elements for any dialogue. Meaning-centered psychotherapy was developed to alleviate the existential distress of cancer patients, and its application may promote EOLD. The future development of meaning-centered psychotherapy in practice and in research is expected to further promote EOLD.