• Journal of Advanced Research in Ocean Engineering
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• 제4권4호
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• pp.163-173
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• 2018

There are many issues in fluid structure interactions when dealing with the free surface flows in a sloshing tank. For example the problem of how yielding a highly nonlinear wave with a simple forced motion over a short duration is of concern here. Nonlinear waves are generated in a rectangular tank which is forced horizontally; its motion consists of a single cycle of oscillation. One of the objectives is to end up with a shape of the free surface yielding a wide range of critical flows by tuning few parameters. The configuration that is studied here concerns a plunging breaker accompanied with a critical jet where great kinematics are simulated. The numerical simulations are performed with a twodimensional code which solves the fully nonlinear free surface boundary conditions in Potential Theory.

• 여성건강간호학회지
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• 제17권3호
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• pp.265-274
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• 2011

Purpose: This study determined the correlation between nurses' critical thinking disposition; problem solving process; and nursing performance. It also examined the impact of critical thinking disposition and problem solving process on nursing performance. Methods: The data was collected from 419 nurses. Descriptive statistics, t-test, ANOVA, scheffe test, pearson correlation analysis and multiple regression analysis were performed. Results: Nursing performance showed that there were differences according to age, marital status, educational level, total number of years in the career and the length of employment in the present department. The problem solving process showed differences in the educational level. Critical thinking disposition showed differences according to age, educational level and total number of years in the career. Problem solving process and nursing performance showed a positive relationship whereas critical thinking disposition and nurses' performance showed a positive relationship. Factors affecting nursing performance, were nurses' age, duration of employment in the present department, problem solving process and critical thinking disposition. This model was statistically significant and showed 22.1% of the total variance. Conclusion: The attention of nursing administrators should be drawn to the consideration that a certain amount of experience in the current department is positively related to nursing performance. Furthermore, in order to provide a improvement in professional nursing performance, educational programs towards nurses' critical thinking disposition and problem solving process should be provided.

• 한국초전도ㆍ저온공학회논문지
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• 제25권1호
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• pp.16-20
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• 2023

The International Electrotechnical Commission (IEC) 61788-26:2020 provides guidelines for measuring the critical current of Rare-earth barium copper oxide (REBCO) tapes using two methods: linear ramp and step-hold methods. The critical current measurement criterion, 1 or 0.1 μV/cm of electric field from IEC 61788-26 has been normally applied to REBCO coils or magnets. No-insulation (NI) winding technique has many advantages in aspects of electrical and thermal stability and mechanical integrity. However, the leak current from the NI REBCO coil can cause distortion in critical current measurement due to the characteristic resistance which causes the radial current flow paths. In this paper, we simulated the NI REBCO coil by applying both linear ramp and step-hold methods based on a simplified equivalent circuit model. Using the circuit analysis, we analyzed and evaluated both methods. By using the equivalent circuit model, we can evaluate the critical current of the NI REBCO coil, resulting in an estimation error within 0.1%. We also evaluate the accuracy of critical current measurement using both the linear ramp and step-hold methods. The accuracy of the linear ramp method is influenced by the inductive voltage, whereas the accuracy of the step-hold method depends on the duration of the hold-time. An adequate hold time, typically 5 to 10 times the time constant (τ), makes the step-hold method more accurate than the linear ramp method.

• Structural Engineering and Mechanics
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• 제73권2호
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• pp.181-190
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• 2020

In this paper, non-linear dynamic buckling behaviour of laminated composite curved panels subjected to dynamic in-plane axial compressive loads is studied using finite element methods. The work is carried out using the finite element software ABAQUS. The curved panels are modelled with S4R element and the nonlinear dynamic equilibrium equations are solved using the ABAQUS/Explicit algorithm. The effect of aspect ratio, radius of curvature and thickness are studied. The importance of orientation of plies in the direction of loading is also reiterated in this study. Vol'mir's criterion is used to calculate the dynamic buckling loads. The panels are subjected to rectangular pulse load of various amplitude and durations and the responses are observed. For particular loading amplitude, a critical value of loading duration is observed beyond which the variation of dynamic buckling load is insignificant. It is also observed that, the value of dynamic bucking load reduces as the loading duration is increased though the reduction is not much after a particular loading duration.

• 말소리와 음성과학
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• 제10권2호
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• pp.39-44
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• 2018

The purpose of this study is to investigate the English pronunciation for high-leveled adult Korean speakers based on pronunciation proficiency test. For this purpose, one native English speaker and eight Korean speakers' suprasegmental features such as sentence F0, standard deviation of vowels and stressed / unstressed vowels' F0, duration and intensity were measured and analyzed. The major results show that (1) high-leveled adult Korean speakers' sentence F0 was similar to that of native English speaker, (2) vowel durations, were less diverse than those of native English speakers, and (3) high-leveled adult Korean speakers utilize vowel duration more actively than F0 to indicate the stress assignment of vowels.

• 대한의생명과학회지
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• 제30권3호
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• pp.169-172
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• 2024

Asthma is a chronic lung disease characterized by wheezing, cough, and chest pain. The objective of this study was to examine asthmatic effect due to house dust mite (HDM) according to age and exposure duration. Asthma induction in young (6 weeks) and old (12 months) aged C57BL6/J mice was accomplished by HDM administration. Bronchoalveolar lavage fluid (BALF) was collected. Inflammatory cells in BALF were counted. Mucus production in lung tissues was evaluated by periodic acid Schiff (PAS) staining. Intraperitoneal (i.p.) and intranasal (IN) injection of HDM induced infiltration of inflammatory cells into lungs of mice. The increase of total cells was higher in young mice than in old mice. Mucus secretion from goblet cells increased after HDM administration, with young mice showing higher mucus production than old mice. In chronic asthmatic state induced by i.p. and IN (three times) injection, old mice exhibited more inflammatory cells, specifically eosinophils, and mucus production than young mice. Our findings suggest that age and exposure duration are critical factors in different manifestations of asthma. Thus, they should be overarchingly considered in drug development for asthma.

• 한국건설관리학회논문집
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• 제7권1호
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• pp.148-158
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• 2006

공공발주기관의 동절기 공사불능기간의 운영은 공사기간을 길게 하고, 건설사업비를 증가시킨다 또한, 건설인력의 활용을 어렵게 하여 근로소득을 감소시킴으로써 국가 경제에도 나쁜 영향을 미친다. 그러므로 동절기에도 골조공사는 시행되어야 할 것이다. 그러나 동절기에 골조공사만 시행하고 마감공사를 시행하지 않을 경우, 골조공사의 빠른 진척이 마감공사의 주공정선에 영향을 미치게 됨으로 이에 대한 규명이 필요하다. 본 연구에서는 동절기 골조공사 시행이 마감공사의 주공정선의 작업기간에 미치는 영향을 규명하였다. 이를 위해 가상현장을 설정한 후, 이 현장을 대상으로 마감공사의 공정표와 주공정선, 전체 공정표 및 주공정선을 작성하고, 공정시뮬레이션을 실시하였다. 본 연구결과는 동절기 골조공사 시행 시 아파트 공사의 공기산정에 유용하게 활용될 수 있을 것이다.

• Journal of Trauma and Injury
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• 제32권3호
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• pp.150-156
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• 2019

Purpose: To determine whether a peripherally inserted central catheter (PICC) meets the goals of a low infection rate and long-term use in trauma patients. Methods: From January 2016 to June 2018, the medical records of patients who underwent central venous catheterization at a level I trauma center were retrospectively reviewed. Data collected included age, sex, injury severity score, site of catheterization, place of catheterization (intensive care unit [ICU], emergency department, or general ward), type of catheter, length of hospital stay during catheterization, types of cultured bacteria, time to development of central line-associated bloodstream infection (CLABSI), and complications. Results: During the study period, 333 central vein catheters (CVC) were inserted with a total of 2,626 catheter-days and 97 PICCs were placed with a total of 2,227 catheter-days. The CLABSI rate was significantly lower in the PICC group when the analysis was limited to patients for whom the catheter was changed for the first time in the ICU after CVC insertion in the ER with similar indication and catheter insertion times (18.6 vs. 10.3/1,000 catheter-days, respectively, p<0.05). The median duration of catheter use was significantly longer in the PICC group than in the CVC group (16 vs. 6 days, respectively, p<0.05). Conclusions: The study results showed that the duration of catheter use was longer and the infection rate were lower in the PICC group than in the CVC group, suggesting that PICC is a safe and reliable alternative to conventional CVC.

• 한국건설관리학회논문집
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• 제10권2호
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• pp.26-33
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• 2009

건설사업의 단계별 진행에 따라서 공정 스케줄의 정확도에 대한 요구수준이 달라진다. 본 연구의 목적은 건설사업의 초기단계에서 활용할 수 있는 표준공정모델을 제시하여 신속하게 전체 개략공기를 산정하는 체계를 제시하는 것이다. 표준공정모델을 적용하여 작업공정을 모듈화하고, Top-down 식 접근으로 상위레벨에서 공정모듈 간 작업연관관계를 분석함으로써 신속하게 프로젝트의 공사기간을 산정할 수 있다. 표준공정모델의 타당성을 검증하기 위해서 각 공정모듈의 작업기간이 일정하다고 가정하고, 가스 플랜트 공정에 대하여 적용시켰다. 그 결과 표준공정모델을 사용하여 계산한 개략 공사기간과 공정관리 툴을 사용한 상세 공사기간은 -3.1% 부터 +15.0%까지의 범위에서 차이를 가졌다. 이러한 결과는 제시된 표준공정모델이 일정 수준의 신뢰성을 가지는 공정 스케줄 정보를 제공하고, 사업기획과 타당성 분석 등 건설사업의 초기단계에서 신속하게 의사결정을 도울 수 있다는 것을 보여준다.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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• pp.337-342
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• 1996

In prevoius works we have repored phonetic similarities between Japanese and Spanish voweis and syiiabic sounds. (1) (2) (3) (4). In the present communication we explore the relative importance of duration of the consonantal segment to elicit Spanish /l/ - /r/ distinction by native j Japanese talkers. Three Argentine and three trained native Japanese talkers recorded /l-r/ combined with /a/ in VCV sequences. Modifications of consonant duration and vowel context with transitions were m made by editing natural /ala/ sounds. Mixed VCV were produced by combining sounds of both languages. Perceptual tests were produced by combining sounds of both languages perceptual performed presenting the speech material, to native t trained and non trained Japanese listeners. In a tirst sessIOn a d discrimination procedure was applied. The items were arranged in pairs a and listeners Nere told to indicate the pair that sounded different. In the f following session they were asked to identify and type the letter corresponding to each one of the items. Responses arc examined in tenns of critical duration of the interval between vowels. Preliminary results indicate that the duration of intervocalic intervais was a relevant cue for the identification of /l/ and /r/. It seems that to differentiate the two sounds, Japanese listeners required relatively longer interval steps than the argentine suhjects. There was a tendency to conhlse more frequently /l/ for /r/ than viceversa.