• 한국철도학회논문집
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• 제10권3호
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• pp.264-270
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• 2007

Two modulus, strain modulus $(E_v)$ and subgrade reaction modulus $(K_{30})$ are being used as a standard for bearing stiffness in Korea Railroad design. The first is used in Europe and the other is used in Japan. The methodologies to obtain the two modulus are similar in using plate. But testing methods are different in loading to plate. Therefore, according to soil strain range, there should be large gap in not only computations of deformation modulus but also the necessary time to test. At first, this paper focuses on the two kinds of test methods to evaluate bearing stiffness. Secondly, based on elastic theory, the theory to obtain the two coefficients are studied thoroughly. Finally, the correlations between the two coefficients were analyzed and evaluated based on the field test results more than 38 places. The matching values for subgrade and ground between $K_{30}$ and $E_{v2}$ are proposed with the consideration of the proposed strain reduction factor (1.5 for subgrade and 3 for ground) and safety factor, respectively.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1078-1083
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• 2008

In this paper, assessed are the stability of vehicle and track according to vertical support stiffness difference on the transition between conventional and zero-longitudinal resistance (ZLR) rail fastener on bridge. For this, the spring constants of rail fastener have been determined according to different load ranges - KTX load (with or without impact factor) and test load of EN standards - from results of laboratory test on rail pad, the stability analysis of vehicle and track has been performed according to numbers or installation length of ZLR fasteners using vertical vehicle-track coupled model to consider train-track interaction. The analysis results reveal that only the wheel load variation slightly exceed the limit value when 2 ZLR fasteners are used with spring constant determined within the EN test load range, but, in all other cases, all evaluation items are satisfied. Thus, it can be said that the stability of vehicle and track will not be degraded by ZLR fastener.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1050-1055
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• 2008

The demand on a turnout layed on a bridge is rising owing to the increasing number of stations on the viaduct. And also the demand on a turnout with CWR is rising to upgrade running speed of the passing train. A CWR with turnout is subjected to additional axial force induced by the thermal expansion of bridge as well as lead rail of turnout. The additional axial force is closely related with the distance between bridge expansion joint and turnout when it is located near the movable bearing of bridge, and it is required to keep some distance to prevent excessive axial stress in CWR. But, there is no guideline in specification for the proper distance from E.J. to turnout, and it caused problem in planning turnout or bridge. So, it this study, the parametric study to investigate the effect on axial stress in CWR with turnout according to span length and distance between bridge expansion joint and turnout was performed. From the results of numerical analysis, it was found out that $5{\sim}30m$ distance is required to prevent excessive axial in CWR for span length less 90m.

• Child Health Nursing Research
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• 제27권4호
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• pp.395-403
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• 2021

Purpose: This study aimed to identify the mediating and moderating effects of mindset and psychological collectivism, respectively, on the relationship between grit and nursing intention for children with emerging infectious diseases, including coronavirus disease 2019 (COVID-19), among pediatric nurses. Methods: We conducted a cross-sectional descriptive study with 230 pediatric nurses. Results: Grit directly impacted mindset (β=.27, p<.001) and nursing intention (β=.20, p=.001). The direct effect of mindset on nursing intension (β=.28, p<.001) and the indirect effect of grit on nursing intension via mindset (β=.08, p<.001) were significant. Accordingly, mindset mediated the effect of grit on nursing intention. The effects of grit and psychological collectivism (β=.19, p=.003), respectively, on nursing intention were significant. However, the interaction between grit and psychological collectivism was not significant. Thus, psychological collectivism did not moderate the effect of grit on nursing intention. Conclusion: The findings demonstrate the importance of pediatric nurses' grit and mindset on their intended care for patients in critical situations. Cultivating a gritty culture and developing interventions to enhance nurses' personality traits associated with their performance will be crucial, and such measures are especially salient for pediatric nurses to face the new adjustments required in the era of COVID-19.

• 공업화학
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• 제32권6호
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• pp.679-683
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• 2021

양친매성 인지질의 한 종류인 레시틴은 데케인과 같은 비극성 유기용매상에서 구형의 역마이셀을 형성한다. 염화리튬과 같은 이온이 레시틴용액에 첨가될 때, 유기졸이 역실린더형 마이셀의 얽힘으로 인해 유기젤로 변환하게 된다. 이번 연구에서, 우리는 레시틴과 염화리튬 혼합물의 유변학적 성질에 대한 보조계면활성제로서의 펜탄올 효과를 연구하고자 한다. 유변학 연구를 통해, 유기젤에 펜탄올이 첨가될 때, 유기젤의 점도와 탄성 성질이 감소하였다. 이러한 감소는 역실린더 마이셀의 길이의 감소가 그 원인이며, 엑스선 소각 산란분석기를 통해 이를 확인하였다.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.179-184
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• 2019

Sparganosis is a parasitic infestation caused by sparganum, a plerocercoid tapeworm larva of the genus Spirometra. Since the first case of human sparganosis reported in 1908, sparganosis has been a global disease, and is common in China, Japan, and Southeast Asian countries. Consumption of raw snakes, frogs, fish, or drinking contaminated beverages are sources of human infections. Human sparganosis usually manifests in subcutaneous fat in areas such as the abdomen, genitourinary tract, and limbs. Breast sparganosis cases are rare, representing less than 2% of total cases of human infections. Complete surgical extraction of the sparganum is the treatment of choice. Because of the rarity of the disease, clinical suspicion is vital to reach the diagnosis of breast sparganosis. Here we report 2 rare cases of breast sparganosis presenting with a painless breast lump, both treated with surgical excision and sparganum extraction.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.407-412
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• 2018

In this study, we have made a cement based inorganic insulation material and added CSA (Hauyne Clinker) to reduce the demolding time and enhance the handling workability. CSA contents were varied by 0%, 1%, 3%, 5% and the atmospheric steam curing was tried for enhancing the compressive strength. As the CSA contents are increased to 5%, a rapid reaction of hydration caused the sinking of the slurry. So, the setting-retarder was added to control the reaction of hydration. By this, the sinking of the slurry was controlled but the height of the green body after expansions was a little bit lowered. In the CSA-added slurry, it was possible to demold within 24 hours and in case of CSA 5%-added, the sufficient workability was secured. Atmospheric steam curing (temperatures $-40{\sim}80^{\circ}C$, for 6~10 hrs.) was attempted to improve the compressive strength and found that an excellent strength of 0.25 MPa was achieved at $80^{\circ}C$ for 8 hrs. Specific gravity was about $0.12{\sim}0.13g/cm^3$ and heat conductivity was about 0.045 W/mK in all specimens. This strategy significantly improves the compressive strength of CSA 5%-added specimen up to 25% compared to without CSA added specimen.

• 한국간호교육학회지
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• 제27권1호
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• pp.29-38
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• 2021

Purpose: The purpose of this study was to describe the meaning of incivility experienced by nursing students in relations with nurses during clinical practice. Methods: This is a descriptive qualitative study that included thirty participants using convenience sampling in universities in S, J, Ch, and C provinces. Data saturation was achieved and methodological rigor was established. Qualitative content analysis was used to inductively determine categories. Results: The four categories derived from analysis were 'left alone at clinical field', 'treated as an assistant', 'not respected as a person' and 'ignored future dreams'. Conclusions: Nursing students continue to carry out repetitive, low-risk tasks, for which they are not properly trained due to the lack of practical guidance in clinical practice. During clinical practice, they are not respected as persons by nurses and are negatively influenced by nurse professionals. A solution to this requires organic cooperation and policy preparation at universities and hospital sites to improve practical training of nursing students.

• 임상간호연구
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• 제27권2호
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• pp.187-198
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• 2021

Purpose: This study aimed to develop an evidence-based nursing practice guideline for preventing postoperative pulmonary complications (PPCs). Methods: The guideline adaptation process was conducted through the 24 steps based on the guideline adaptation manual of Korean Hospital Nurses Association. Results: The newly developed guideline to prevent PPCs consisted of four domains and 30 recommendations. The number of recommendations in each domain was 7 for assessment of PPCs, 17 for nursing interventions to prevent PPCs after general anesthesia, 4 for education (intended for patients and medical staff), and 2 for monitoring and recording. Conclusion: The developed guidelines will contribute in standardization of nursing practice and PPCs prevention and management. We recommend the dissemination and utilization of these guidelines nationwide to improve the quality of postoperative pulmonary complication prevention.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.524-533
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• 2021

In this study, a series of anion conductive organic/inorganic composite membranes with excellent ionic conductivity and chemical stability were prepared by introducing graphene oxide (GO) inorganic nanofiller into the quaternized poly(phenylen oxide (Q-PPO) polymer matrix. The fabricated organic/inorganic composite membranes showed higher ionic conductivity than the pristine membrane. In particular, Q-PPO/GO 0.7 showed the highest ionic conductivity value of 143.2 mS/cm at 90℃, which was 1.56 times higher than the pristine membrane Q-PPO (91.5 mS/cm). In addition, the organic/inorganic composite membrane showed superior dimensional stability and alkaline stability compared to the pristine membrane, and the physicochemical stability was improved as the content of inorganic fillers increased. Therefore, we suggest that the as-prepared organic/inorganic composite membranes are very promising materials for anion exchange membrane applications with high conductivity and alkaline stability.