• Structural Engineering and Mechanics
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• 제62권2호
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• pp.179-196
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• 2017

The paper focuses on dynamic analyses of a series of simply-supported symmetric composite steel-concrete bridges loaded by an ICE-3 train moving at high speeds up to 300 km/h. The series includes five bridges with span lengths ranging from 15 m to 27 m, with repeatable geometry of the superstructures. The objects, designed according to Polish standards valid from 1980s to 2010, are modelled on the bridges serviced on the Central Main Line in Poland since 1980s. The advanced, two-dimensional, physically nonlinear model of the bridge-track structure-high-speed train system takes into account unilateral nonlinear wheel-rail contact according to Hertz's theory and random vertical track irregularities equal for both rails. The analyses are focused on the influence of random track irregularities on dynamic response of composite steel-concrete bridges loaded by an ICE-3 train. It has been pointed out that certain restrictions on the train speed and on vertical track irregularities should be imposed.

• 한국항해학회지
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• 제15권3호
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• pp.73-97
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• 1991

The analysis and investigation are described for White's[2] equations compared to the equations of Runeburg[3] and Milano[5] for continuous icebreaking mode, Tunik[8-1] and Ghoneim[8-2] for ramming icebreaking mode. Calculation results compare reasonably well with published model-scale and full-scale icebreaker data by Baker[1] and Dick[11]. During continuous and ramming mode operation, using characteristics of an incebreaker, down ward force on ice and standard ice thickness broken are predicted. Additionally draft, trim and extraction difficulty are also predicted. The bow part line of an icebreakin $g^{ply}$ vessel is designed aiming to maximize the ice breaking capabiltiy as following conditions-low bow angle[20 degrees] at designed waterline, small spread angle complement [6 degrees] at designed waterline, small spread angle complement [6 degrees] and high propeller thrust [220tons]. with plow, two reamers and wave type bumper.

• 대한원격탐사학회지
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• 제3권2호
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• pp.89-102
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• 1987

Microwave remote sensing plays a major role in areas where cloud cover and darkness prevail. In this and the next paper, models are described for the radar backscatter from two major types of sea ice in an attempt to specify optimum sensor parameters and to allow the most reliable image interpretation possible. Here, the physical-optics model using an exponential correlation function is shown to be able to presict the signatures of first-year ice under cold conditions. The effect of volume scattering by small inclusions in the first-year ics is shown to be negligible using a semi-empirical volume scattering model.

• 천문학회보
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• 제46권1호
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• pp.57.1-57.1
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• 2021

The icy mantles of interstellar grains are developed by the freeze-out of interstellar molecules and atoms onto grain surfaces. The ice molecules become more complex by surface chemistry induced directly by high energy photons or by the thermal energy diffused over heated grain surface. Therefore, the ice composition is an important tracer of physical conditions where the ices form. Ices have been studied via their absorption features against continuum sources, such as young stellar objects or evolved background stars, in infrared wavelengths. The Spitzer IRS was the most sensitive spectrometer for the observations of infrared ice absorption features. We has been developing an automated analysis tool for the Spitzer IRS spectra, especially for the 15 ㎛ CO₂ bending mode. The 15 ㎛ CO₂ absorption feature is very useful for the study of accretion process in star formation since its spectral shape varies with thermal condition of the dust grains. Eventually, this tool will cover the whole range of the Spitzer IRS spectrum (5~20 ㎛).

• 아태비즈니스연구
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• 제14권2호
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• pp.153-165
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• 2023

Purpose - The purpose of this study is to derive sub-group of Chinese residents to Harbin International Ice and Snow Festival through market segmentation and to identify their characteristics of each group. Design/methodology/approach - The survey was conducted with a total of 405 Chinese residents, and empirical analysis was conducted using SPSS program. Findings - As a result of the analysis, four factors were derived. Based on the factors, four sub-markets were derived by conducting cluster analysis for market segmentation. Market strategies for each sub-group were discussed based on significant differences between clusters according to demographic characteristics. Research implications or Originality - The results of this study contribute to find out potential target market of Chinese residents, and to provide data for better positing of Harbin International Ice and Snow Festival.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제6권1호
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• pp.1-9
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• 2003

목 적: Helicobacter pylori (H. pylori)에 의한 질병 발생의 병독 인자로 cagA, picB 및 iceA 등의 유전형이 연구되고 있으며, 최근에는 위 상피세포의 증식(proliferation)과 세포사(apoptosis)의 불균형이 중요시되고 있다. 이에 H. pylori 감염 소아에서 위 상피세포 증식과 세포사 및 cagA, picB 및 iceA 유전형의 관련성을 알아보고자 하였다. 방 법: 1999년 8월부터 2001년 6월까지 이화여자 대학교 목동병원 소아과에서 소화기 증상으로 내시경을 시행하여 H. pylori 감염으로 진단된 20예와 감염 음성 20예를 대상으로 하였다. H. pylori 감염 양성은 조직학적으로 H. pylori 균이 관찰되고, CLO 검사와 ureC PCR이 전부 양성인 경우로 하였다. 위생검 조직에서 개정된 시드니 체계를 이용하여 조직 소견을 분석하고, proliferating cell nuclear antigen (PCNA) 발현으로 위 상피세포 증식의 정도를 in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) 방법으로 세포사의 정도를 조사하였다. cagA, picB 및 iceA 유전자에 대해 중합효소연쇄반응을 시행하였다. 결 과: 1) 세포 증식 지표는 H. pylori 감염 양성에서 $77.4{\pm}13.12$로 음성 $52.3{\pm}12.20$에 비하여 유의하게 높았다(p=0.000). 세포 증식 지표는 H. pylori 밀도가 증가할수록(r=0.624, p=0.000, 다핵형 중성구의 활동성이 증가할수록(r=0.460, p=0.005), 만성 염증이 증가할수록(r=0.433, p=0.009) 증가하였다. 2) 세포사 지표는 H. pylori 감염 양성에서 $0.70{\pm}0.411$, 음성에서 $0.14{\pm}0.201$로 감염 양성에서 음성보다 유의하게 높았다(p=0.000). 세포사 지표는 H.pylori 밀도가 증가할수록(r=0.691, p=0.000), 다핵형 중성구의 활동성이 증가할수록(r=0.585, p=0.000), 만성 염증이 증가할수록(r=0.535, p=0.001) 증가하였다. 3) 세포 증식 지표가 증가할수록 세포사 지표는 유의하게 증가하였다(r=0.527, p=0.001). 4) H. pylori 감염 양성에서 유전형의 양성률은 cagA 90%, picB 75%, iceA1 60% 및 iceA2 15%였으며, cagA, picB, 및 iceA 유전형에 따른 세포 증식지표, 세포사 지표, 내시경 소견 및 조직 소견에는 유의한 차이가 없었다. 결 론: H. pylori 감염 소아에서 위 상피세포 증식 지표와 세포사 지표가 균형을 이루면서 증가하였으며, cagA, pic B 및 iceA 유전형에 따른 유의한 차이는 없었다. 이는 위 상피세포 증식과 세포사가 H. pylori의 병인에 중요함을 시사하며, 앞으로 세포 증식과 세포사의 기전과 유발 요인, 여러 유전형과의 관계, 성인과의 비교 연구 등이 필요하리라 생각된다.

• 대한간호학회지
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• 제25권2호
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• pp.341-350
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• 1995

A quasi-experimental study was conducted to examine the effect of ice pack application to post cardiac surgery toddlers before C-tube removal. Twenty toddlers aged 13 months to 24 months, who were admitted to the hospital for open heart surgery during the period from July, 1993 to October, 1993 were randomly assigned to the experimental or control group. An ice pack was applied to the C-tube insertion site for 8 minutes before C-tube removal for the experimental group. The children were videotaped during the procedure to assess pain behavior and crying time. The score on the Modified Behavioral Pain Scale(MBPS), crying time, and vital signs were measured to determine the effect of ice pack application. The data were analyzed using Mann-Whitney U test, Paired t-test, and Pearson correlation coefficient. The result of the study are as follows : 1. There was a significant difference between the experimental group and the control group in pain behavior (U=17.0, p=.01). 2. There was no significant difference between the two groups in crying time. 3. There was a significant difference between the two groups in heart rate (U=24.5, p=.05). 4. There was a significant difference between the two groups in systolic blood pressure (U=24.0, p=.05) 5. There was a significant difference between the two groups in diastolic blood pressure (U=23.0, p=.04). 6. There was no significant difference between the two groups in respiration rate. 7. Pain behavior was significantly correlated with heart rate, systolic blood pressure, and crying time (r=.50, .54 and .59, p<.05). The result showed that the ice pack application was effective to reduce pain related to C-tube removal for the toddlers. From the study, it is recommended that the effectiveness of the cold ap-plication to children undergoing different painful procedures be examined to determine the most effective length of cold application to reduce pain in children.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.517-522
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• 2013

아이스크림제조기는 원액통과 냉각통의 증발온도가 $4^{\circ}C$와 $-8^{\circ}C$로 각각 다르므로 다수의 모세관을 이용하는데 이 경우 서로 냉매 유량에 영향을 주므로 냉동사이클 설계가 복잡하다. 본 연구에서는 증발온도가 서로 다른 두개의 증발기(냉장 및 냉동)가 장착된 소프트 아이스크림 제조기의 성능을 해석하였다. 압축기 해석에는 효율모델을 적용하였고, 모세관은 1차원 유동으로 간주하여 해석하였으며, 응축기와 증발기는 UA-LMTD법을 적용하여 해석하였다. 요소부품에서의 엔탈피, 압력 및 질량의 평형을 적용하여 냉동사이클 시뮬레이션 프로그램을 개발하였고 R404A를 사용하는 아이스크림 제조기에 적용한 결과, 냉장과 냉동 증발기의 온도를 $3^{\circ}C$ 이내로 예측하여 측정치와 대체로 일치하였다.

• 에너지공학
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• 제19권4호
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• pp.234-239
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• 2010

원형 파이프를 유동하는 6.5% EG 수용액으로부터 만들어진 아이스슬러리의 열전달 특성을 분석하기 위한 실험을 수행하였다. 실험 장치의 시험부는 13.84 mm 내경과 1,500 mm의 길이를 가진 동관으로 제작되었다. 아이스슬러리는 시험부 주변에 이중관 형태로 만들어진 원형관 내부를 유동하는 온수에 의해 가열되었다. 본 연구의 실험에 적용된 IPF와 질량 유속은 각각 0 ~ 25% 그리고 1000 ~ 3,000 kg/$m^2s$의 범위이었고, 온수의 온도와 유량은 일정하게 유지하였다. 측정된 열전달량은 질량 유량과 IPF가 증가함에 따라 증가하였으나, IPF의 영향은 높은 질량 유량에서는 작은 것으로 나타났다. 낮은 질량유량에서는 열전달 계수의 급격한 상승이 15 ~ 20%의 IPF에서 나타났다. 마지막으로 측정된 열전달계수는 기존의 열전달상관식들에 의해 계산된 열전달계수와 비교하여 제시하였다.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 정기총회 및 제35차 춘계 학술 발표대회
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• pp.290-296
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• 2005

This study was carried out to develop the efficient freeze concentration process of milk through controlling the recrystallisation phenomena of ice. Freeze-concentration was progressed with multi-stage freeze concentrator and there was artificial temperature control to induce recrystallisation phenomena. In each stage of freeze concentration process, the regular recrystallisation time was fixed as 1, 2, 4 and 8 hr to compare the solute increment, yield, brix and ice-crystal size among experimental conditions. Higher concentration as total solids was observed due to the elapse of recrystallisation time, and the maximum total solids in final products: 32.67% was obtained at the ripening time of 8 hr in two-stage process. This result was excessively high concentration comparing to the existing researches and presented the possibilities of milk freeze concentration in the dairy industry, The results of brix and ice-crystal size showed the direct correlation with the recrystallisation time that meant the increased processing time showed the increment of brix and ice-crystal size. Obtained results were numerically modelled to predict the progress of concentration in the industrial process and all of them had fairly high R2 of determination. Therefore, we regarded that these numerical models could be utilized for the development of efficient technology in industrial freeze concentration process.