• 한국자동차공학회논문집
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• 제4권6호
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• pp.144-152
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• 1996

In the sequential MPI system with one injection for each cycle, engine performance is influenced by the mixture conditions. It can be said that engine performance is improved by being better identical mixture formation conditions for all cylinders. As the fuel injection timing to the intake port effects on the mixture formation conditions and the engine performance, injection timing must be better adjusted to engine requirements. Engine behavior was clearly different depending on the injection time during intake storke. Therefore it was studied that injection timing of fuel effects on the engine performance I. e. combustion stability, COV(imep), A/F excursion, CO,HC emission concentration and fuel consumption. It was found that late intake-synchronous injection was deteriorated the combustion characteristics and performance characteristics, while early intake-synchronous infection resulted in favorable engine behavior.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.349-355
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• 1996

In this study, the mechanistic critical heat flux (CHF) model and correlation for water are derived based on flow excursion (or Ledinegg instability) criterion and the simplified two-phase homogeneous model. The relationship between CHF for the water and the principal parameters such as mass flux heat of vaporization, heated length-to-diameter ratio, vapor-liquid density ratio and inlet subcooling is derived on the developed correlation. The developed CHF correlation predicts very well at the applicable ranges, 1 < P < 40 bar, 1, 300 < G 27, 00 kg/$m^2$s and inlet quality is less than -0.1. The overall mean ratio of predicted to experimental CHF value is 0.988 with standard deviation of 0.046.

• 자원환경지질
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• 제10권3호
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• pp.159-162
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• 1977

• 대한간호학회지
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• 제48권1호
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• pp.26-37
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• 2018

Purpose: The aim of this study was to evaluate the effects of active mandibular exercise (AME) in patients with limited mouth opening after maxillomandibular fixation (MMF) release. Methods: The study used a quasi-experimental, nonequivalent control group and a pre test-post test design. Sixty-two patients with Maxillomandibular Fixation Release were assigned to the experimental (n=31) or control group (n=31). The AME was performed in the experimental group for 4 weeks. The exercise AME consisted of maximal mouth opening, lateral excursion and protrusive movement. These movements were repeated ten times a day. After the final exercise of the day, the number of tongue blades used for mouth opening was noted. The effect of AME was evaluated after MMF release at different time intervals: a) immediately, b) after 1 week, c) after 2 weeks, d) after 4 weeks, and e) after 12 weeks. The exercise was assessed using the following criteria: a) mandibular movements, b) pain scores associated with maximal mouth opening, c) discomfort scores associated with range of movement, and d) daily life activities that involve opening the mouth. Results: The experimental group showed significant improvement regarding the range of mandibular movements (maximal mouth opening (F=23.60, p<.001), lateral excursion to the right side (F=5.25, p=.002), lateral excursion to the left side (F=5.97, p=.001), protrusive movement (F=5.51, p=.001)), pain score (F=39.59, p<.001), discomfort score (F=9.38, p<.001). Daily life activities that involve opening the mouth were more favorable compared to those in the control group. Conclusion: The AME in patients after MMF release is helpful for increasing mandibular movement range, decreasing pain and discomfort, and improving day life activities that involve opening the mouth. Therefore, AME is highly recommended as an effective nursing intervention.

• Journal of Oral Medicine and Pain
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• 제22권2호
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• pp.207-217
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• 1997

This study was performed for Investigation of the magnitude of mandibular positional change in maximum mouth opening. protrusion, lateral excursion, gum and peanut chewing with BioPAK system(Bioresearch Inc. USA) which can analyze mandibular rotational torque movements. For this study 17 female patients with Temporomandibular joint(TMJ) closed lock and 18 female control without any Temporomandibular disorders(TMDs) signs and premature occlusal contact were included. The obtained results were as follows : 1. In maximum mouth opening, the mandibular rotational angle and distance of patients were significantly greater than those of control group in horizontal plane(P<0.05). 2. In protrusion, the mandibular rotational angle and distance of patients were significantly greater than those of control group in frontal and horizontal plane(P<0.01, P<0.05). 3. The mandibular rotational angle and 야stance in lateral excursion to affected side of patients were significantly greater than those in lateral excursion to non-affected side in frontal plane(P<0.05). 4. The mandibular rotational angle in gum chewing to affected side of patients was significantly greater than that in gum chewing to non-affected side in frontal plane. 5. The mandibular rotational angle and distance in peanut chewing to affected side of patients were significantly greater than those in peanut chewing to non-affected side in frontal and horizontal plane. 6. The mandibular rotational angle and distance in peanut chewing to affected side of patients were greater than those in gum chewing, and was the same result in control group in frontal and horizontal plane.

• The Journal of Advanced Prosthodontics
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• 제9권1호
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• pp.45-51
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• 2017

PURPOSE. This study aims to investigate the effects of four different lateral occlusion schemes and different excursions on peri-implant strains of a maxillary canine implant. MATERIALS AND METHODS. Four metal crowns with different occlusion schemes were attached to an implant in the maxillary canine region of a resin model. The included schemes were canine-guided (CG) occlusion, group function (GF) occlusion, long centric (LC) occlusion, and implant-protected (IP) occlusion. Each crown was loaded in three sites that correspond to maximal intercuspation (MI), 1 mm excursion, and 2 mm excursion. A load of 140 N was applied on each site and was repeated 10 times. The peri-implant strain was recorded by a rosette strain gauge that was attached on the resin model buccal to the implant. For each loading condition, the maximum shear strain value was calculated. RESULTS. The different schemes and excursive positions had impact on the peri-implant strains. At MI and 1 mm positions, the GF had the least strains, followed by IP, CG, and LC. At 2 mm, the least strains were associated with GF, followed by CG, LC, and IP. However, regardless of the occlusion scheme, as the excursion increases, a linear increase of peri-implant strains was detected. CONCLUSION. The peri-implant strain is susceptible to occlusal factors. The eccentric location appears to be more influential on peri-implant strains than the occlusion scheme. Therefore, adopting an occlusion scheme that can reduce the occurrence of occlusal contacts laterally may be beneficial in reducing peri-implant strains.

• 한국방재안전학회논문집
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• 제6권2호
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• pp.23-30
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• 2013

본 연구에서는 최근 2003년부터 2012년까지의 10년 동안 연최대평균풍속이 발생한 날의 변동풍속으로부터 최초파괴확률(FEP: first excursion probability)을 알아보기 위하여 대표지점 8개 지점을 선정하고, 선정된 각 지점에 대한 최근 10년 동안의 풍속자료는 기상청으로부터 획득했고, 90개의 앙상블 중 정규확률분포로 평가된 12개의 모집단을 선정하여, 최초파괴확률 평가를 실시하였다. 분석결과 FEP의 발생확률은 P모델이 M모델 보다 약 60-200% 크게 나타나는 사실을 알 수 있었고 지표면 10 m에서 실측된 기상청자료의 변동풍속으로부터 지상 320 m까지 추정한 변동풍속의 평균 풍속 난류강도의 수직분포를 확인할 수 있었고, 서울 대구의 경도풍 고도는 약 300 m, 나머지 지점은 약 240-280 m로 나타났고, 지표면부근에서의 난류강도는 0.72 m/s-3.3 m/s로 100 m 높이 까지는 난류강도의 변화율이 증가하는 사실을 확인할 수 있었다.

• 한국초등과학교육학회지:초등과학교육
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• 제29권3호
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• pp.326-340
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• 2010

TGT (teams-games-tournaments) cooperative learning is suggested as a method which enables both the individualized teaching-learning and the small group learning in students-centered open education. This study investigated the instructional effects of the pre-learning program applied by ICT-based TGT cooperative module for science museum excursion regarding of the earth and the moon on the science related attitude according to gender difference in elementary school science class. Three classes of third graders (N=87) at a elementary school were randomly assigned to the ICT-based TGT cooperative learning group, the ICT learning group, and traditional learning group. The students were taught about the planning of exploring the moon in the chapter of the earth and the moon, for 1 class hour. Prior to the instructions, the TOSRA(test of science related attitude) and achievement test were administered. Two-way ANCOVA results revealed that the scores of the ICT-based TGT cooperative learning group were significantly higher than the other learning groups for most of the TOSRA scales. However, there was a little significant difference among the three groups in the three distinct scales of TOSRA, Normality of Scientists, Leisure Interest in Science, and Career Interest in Science. Advantage/disadvantage and usefulness of ICT-based TGT cooperative learning were also discussed.

• Physical Therapy Rehabilitation Science
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• 제9권1호
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• pp.25-35
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• 2020

Objective: To compare the effects of joint mobilization, gym ball exercises, and breathing exercises on breathing pattern disorders and joint position sense in persons with chronic lower back pain. Design: Three-group pretest-posttest design. Methods: Thirty-six individuals with chronic low back pain who were undergoing a postural correction and vertebral movement at a rehabilitation center participated in this study. The subjects were randomly divided into the joint mobilization group (n=12), gym ball exercises group (n=12), and the breathing exercises group (n=12). The exercises were applied for 40 minutes a day, twice a week for a total of 12 weeks. Measurement tools included the end-tidal CO₂ (ETCO₂), respiration rate (RR), breath hold time, Nijmegen Questionnaire (NQ), excursion, and joint position error (JPE). Results: The groups showed significant differences in the ETCO₂, RR, NQ, Excursion and JPE test before and after the intervention (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in ETCO₂ and RR (p<0.05). The differences between the groups were most significant in the group that received breathing exercises in NQ and excursion (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in JPE Lt. and Rt. (p<0.05). Conclusions: All three interventions had a significant impact on the biomechanical changes, respiratory variables, and joint position sense in participants with chronic lower back pain. Breathing exercises were found to be particularly effective in improving respiratory parameters.

• 한국해안·해양공학회논문집
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• 제23권3호
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• pp.193-204
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• 2011

역동적인 파랑에 노출되는 경우 다양한 failure mode를 쉽게 드러내는 Oil boom의 성능을 개선하기 위해 가장 정교한 파랑모형인 spatially filtered Navier-Stokes 식을 LES (Large Eddy Simulation), 잔차응력에 대한 LDS (Lagrangian Dynamic Smagorinsky 모형), SPH (Smoothed Particle Hydrodynamics) 기법을 활용하여 해석하는 새로운 수치모형이 제언되었다. 이어 부유식 Oil Boom의 누유특성을 규명하기 위해 oil spill, progressive wave, oil boom의 상호작용을 oil boom이 계류삭에 고정되어있는 경우와 oil boom의 excursion이 허용된 경우에 대해 각각 수치모의 하였다. 모의결과 oil boom의 skirt 길이가 수심의 30% 이상이고 excursion이 허용된 경우 oil spill의 차폐 기능은 극대화되는 것으로 밝혀졌다. 이와 더불어 y = 1~2 m 사이에 오일막과 해수의 경계층에서 생성된 와류가 저면으로 확산되면서 시계방향과 반 시계방향의 와류가 엇갈리게 생성되는 coherent eddies가 관측되어 수리실험을 통해 그 존재가 알려진 Kelvin-Helmholz파의 성장과정과 계면으로부터의 일탈과정이 수치모의된 것으로 판단된다.