• The Korean Journal of Zoology
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• v.38 no.1
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• pp.1-9
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• 1995

연두·금파리에서 혈구 세포가 면역반응의 일환으로 일으키는 결절형성(nodule formation) 현상을 형태학적으로 관찰하고자 본 실험이 수행되었다. 연두금파리 종령 유충 체내에 정상 효모, 고정된 대모, 세포액이 제거된 원형질체의 효모를 각각 주입하여 면역반응 과정을 전자현미경으로 관찰하였다 먼저 정상 효모를 주입하였을 경우, 효모와 접촉한 헐구의 과립방출과 곧 이은 혈구의 파괴 그리고 효모 주위에 혈림프와 함께 점액성응혈(clot)의 형성을 관찰 할 수 있었다 점액성 응혈에는 여러 유형의 파괴된 혈구가 포함되어 있었다. 이같은 면역반응에는 체내 혈구 중 과립혈구(granulocyte)가 가장 활발히 반응였고 응혈의 대부분을 형성하였다. 결절의 중심부인 응혈은 대모와 파괴되지 않은 혈구 대 파괴된 혈구 그리고 방출된 과립들로 차 있었고, 효모 주입 3시간 까지는 이같은 응혈은 계속 확대되었다. 그러나 10시간 이후에는 응혈이 관찰되지 않았으며 이때 체강내에서 효모가 관찰되곤 하였다. 고정된 효모를 주입하였을 경우에는 혈구파괴나 과립방출 등이 관찰되지 않았으며, 고정된 효모에 대한 혈구의 식 세포작용만이 관찰되었다. 이 식세포작용은 주입후 10시간 까지 계속되었다. 원형질 체의 효모를 주입하였을 경우에는 혈구에의한 면역반응이 관찰되지 않았다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.165-169
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• 2012

하천에서의 골재 채취는 일시적으로 홍수위를 낮추는 순기능도 있지만 하천형태학적으로 좋지 않은 영향을 줄 수도 있다. 하천에서 골재 채취로 인한 준설웅덩이의 회복에 필요한 시간 혹은 과정은 공학적으로 매우 중요하다. 본 연구에서는 시간에 따른 준설 웅덩이의 발달 과정을 모의할 수 있는 수치모형을 제시하였다. 제시된 수치모형은 준정류 가정에 기초하는데, 이는 흐름은 정상류이고 하도가 변하는 특성시간이 흐름에 비해 길다고 가정하는 것이다. 총유사량 공식으로 Engelund and Hansen (1967) 공식과 Ackers and White (1973) 공식을 이용하여 수치실험을 실시하였다. Engelund and Hansen 공식을 사용하였을 때, Parker (2004)에 제시된 준설 웅덩이의 되메움 과정을 정량적으로 유사하게 모의하는 것으로 나타났다. 제시된 모형의 적용성을 검토하기 위하여 선행 실내실험에 적용하였다. 전반적으로 준정류모형이 준설 웅덩이의 되메움과 전파과정을 잘 모의하는 것으로 확인되었다. 그러나 수치모형이 두부침식 현상을 잘 재현하지 못하여 재퇴적 이후의 하상파를 과소 산정하는 것으로 나타났다.

• Journal of the Korean Geographical Society
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• v.48 no.4
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• pp.557-574
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• 2013

The paper examines the recent criticism from various viewpoints on landscape research in 'New cultural geography' focusing on the representation and duplicity of landscape as one of the key theoretical basis of the landscape school. The paper argues that landscape theories in new cultural geography should be considered as what is constantly changing over time and composed of various theoretical and genealogical elements rather than internally homogeneous, fixed, and closed system of knowledge. Through the recent 'phenomenological turn' of geography, landscape researchers explores a possibility of alternative approach to the existing theories and methods, which is so called NRT(Non-representational theory). The research objectives of the paper is to examine the theoretical and practical implications of such significant criticisms, which put emphasis on the idea of landscape as performance and practice rather than landscape as representation in cultural geography.

• Journal of Korean Library and Information Science Society
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• v.48 no.1
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• pp.161-189
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• 2017

The purpose of this study is to describe the experience of visually impaired academic researchers' use of scholarly contents and to explore intrinsic nature of the experience. In-depth interview was conducted with a total number of twelve visually impaired academic researchers and the data were analyzed using Colaizzi's phenomenological research method. A total of 107 significant statements were extracted, divided into 44 themes and 12 theme clusters. The statements were then classified into four categories. The 'scholarly contents acquisition and use' category has to do with difficulties that these experience when negotiating with internet sites with poor web accessibility and full-text availability. The 'changes in perception and emotions' category deals with transitions in perception and mood experienced by visually impaired academic researchers' over time. The 'relationships with support personnel' category includes issues related with the difficulty of securing support person, support person's inadequate level of competence, and establishing/sustaining personal relationships. Finally, the 'improvement requirements' category includes issues that these researchers want resolved with regard to contents acquisition and use.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.219-228
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• 2022

The purpose of this study is to explore what obstacles adult undergraduate experience in adapting to college life. To this end, in-depth interviews were conducted with 32 adult undergraduate attending colleges in Daegu and Gyeongbuk. For the study, Colaizzi's phenomenological research method was used and analyzed. As a result of the analysis, eight factors such as relation obstacle, bachelor's and curriculum operation obstacle, social recognition obstacle, study ability obstacle, college environment obstacle, economic obstacle, personal disposition obstacle, and temporal obstacle were found. Through the above research results, it was found that the college environment, which is operated mainly by general college students, is expressed as various types of obstacle for adult undergraduate who work and study at various ages and experiences. Based on the derived obstacle factors, it is expected that a follow-up study will be conducted to develop a measurement tool that can empirically explore the obstacle of adult undergraduate to adapt to college life.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.150.2-150.2
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• 2010

가스 하이드레이트는 낮은 온도와 높은 압력 조건에서 물 분자들이 수소 결합을 통해 형성하는 3차원의 격자구조에 저분자량의 기체 분자들이 포획되어 있는 결정성 화합물이다. 가스 하이드레이트는 형성 시 많은 양의 가스를 저장할 수 있는 특성을 가진다. 천연 가스를 심해저로 수송하는 수송관 내부에 가스 하이드레이트가 생성되면 막힘 현상이 일어나 비용과 시간 측면에서 막대한 손실이 일어날 수 있다. 따라서 이를 방지하기 위해 열역학적 상평형 조건을 변화시켜 가스 하이드레이트 형성을 방지할 수 있는 열역학적 저해제에 관한 연구의 필요성이 요구된다. 본 연구에서는 Glycine, Alanine 등의 열역학적 저해제를 5, 10, 15 wt% 등으로 첨가하여 $CO_2$ 하이드레이트의 상평형 조건에 미치는 영향을 측정하였고, 각 물질을 12.5, 22.0 mmol%로 첨가하여 물질에 따라 상평형에 미치는 영향을 비교하여 보았다. 또한 Alanine의 두 가지 광학 이성질체를 같은 농도로 첨가하여 각 물질에 따라 상평형에 미치는 영향을 비교하였다.

• Progress in Medical Physics
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• v.15 no.3
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• pp.167-172
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• 2004

A Siemens HD-270 MLC$^{TM}$, a virtual-micro MLC, allows to the application of a smooth field edge method due to the finite leaf-width of MLC. This technique was implemented into a Pinnacle planning system in order to evaluate the dose distributions during the planning stage. The necessary dosimetric aspects, such as undulation and effective penumbra, were investigated with variations in the resolutions of a virtual-micro MLC and field edge angle. The positional accuracy of the couch movement was also assessed for clinical implementation. The overhead time for planning and treatment was confirmed as negligible.e.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.113-123
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• 2016

The purpose of this study is to understand the elementary student's growth and its implications from the students' experience participating in the science fair by phenomenological study. The results are as follows. First, the students have various experiences. They acquire scientific knowledge and inquiry skills by conducting in-depth experiments, visiting several places, and interviewing experts. They have some experience in writing experiment journals to record the inquiry process in their own language, and presenting their results in public. Second, the students suffer several difficulties while preparing for the science fair. They have some difficulties when the results were not consistent with the hypothesis, or they had to repeat the experiment over and over. They feel burdened in writing the experiment journal. They had a few time to meet friends or for hobbies. Third, the students improve scientific attitude through the science fair, and they receive a positive effect on the affective side. They developed scientific interest, curiosity, cooperation, etc. And they also gained a sense of accomplishment, confidence, friendship, good relationship with teachers, career interest, etc. This study finds out that students participating in the science fair have a lot of experience that cannot be done easily in a normal science class. Even though students confront some difficulties in the inquiry process, they make good progression and feel accomplished. So the science fair is valuable experience for them.

• Journal of The Korean Association For Science Education
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• v.41 no.4
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• pp.283-295
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• 2021

This study attempts to explore the nature of science anxiety experienced by science-gifted middle school students based on Giorgi's phenomenological research method. Among the first-year middle school students selected by the University-affiliated Science Education Institute for the Gifted, six science-gifted students with high levels of science trait anxiety and science state anxiety experience were selected. Two interviews related to experience of science anxiety were conducted with participants. As a result of the analysis, science anxiety experienced by science-gifted students was caused by setting the ideal self-concept, lack of confidence, past experiences, difficulty in contents, and something valuable. Students complained of physical·physiological, cognitive, emotional·psychological discomfort when they felt science anxiety, and recognized it as an opportunity for growth. In addition, science-gifted students were shown to cope with various ways such as confronting uneasy situations directly or refining their minds to overcome various uncomfortable symptoms that arise when science anxiety is triggered. Some students thought that no special efforts were required to lower their level of anxiety because anxiety was relieved over time. The students had both negative and positive meanings for science anxiety. The results of this study will help teachers in-depth understanding of middle school science-gifted students who experience science anxiety and provide a theoretical basis for what kind of educational environment should be created and educational programs should be provided in relation to science anxiety.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.2
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• pp.135-143
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• 2020

Natural drought is a three-dimensional phenomenon that simultaneously evolves in time and space. To evaluate the link between meteorological and hydrological droughts, we defined a drought event from a three-dimensional perspective and analyzed the propagation characteristics in time and spaces. Overall results indicated that 77 % of the total cases of spatio-temporal droughts was propagated based on the single category relationship between meteorological and hydrological drought events, while 23 % was affected by multiple meteorological drought events to the occurrence of hydrological drougts. Especially, it turned out that the hydrological drought was caused by the spatio-temporal effects of the propagation of four meteorological drought events generated due to long-term lack of precipitation in 1994-1995. In addition, the meteorological drought caused by the lack of precipitation in the summer of 2001 lasted for several months, and was propagated to the hydrological drought in April 2002.