• Applied Microscopy
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• 제25권2호
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• pp.39-52
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• 1995

Pinealocytes in the lower vertebrate are known to have photoreceptive function. These photoreceptor cells have been characterized morphologically in various species of lower vertebrates. No such ultrastructural studies, however, were reported in fresh water turtle. The purpose of this study is to characterize the pinealocytes and the phylogenetic evoluton of these cells is discussed in terms of functional analogy. I. Light microscopy: The pineal body was divided into incomplete lobules by connective tissue septa containing blood vessels, and parenchymal cells were arranged as irregular cords or follicular pattern. In the lobules, glandular lumina were present and contained often densely stained materials. II. Electron microscopy: The pineal parenchyma had three categories of cells: photoreceptor cells, supportive cells and nerve cells. The photoreceptor cells had darker cytoplasm compared to the supportive cells, and the enlarged apical cytoplasm(inner segment) containing abundant mitochondria and dense cored vescles protruded into the glandular lumen in which lamellar membrane stacks(outer segment), dense membranous materials, and cilia were present. Some of these lamellated membrane stacks appeared to be dege-nerating while others were apparently newly formed. Constricted neck portion of the photoreceptor cells contained longitudinally arranged abundant microtubules. centrioles and cross-striated rootlets. Cell body had well developed Golgi apparatus, abundant mitochondria, dense granules($0.5{\sim}1{\mu}m$), dense cored vesicles($70{\sim}100nm$), and rough endoplasmic reticulum occasionally with dense material within its cisterna. Basal portion of the photoreceptor cells had basal processes often with synaptic ribbons, which terminate in the complicated zone of cellular and neuronal processes. Synatpic ribbons often made contact with the nerve processes and the cell processes of neighboring cells. In some instances, these ribbons were noted free within the basal process and were also present at the basal cell mem-brane facing the basal lamina. Obvious nerve endings with clear and dense cored vesicles were observed among the parenchymal cells. Photoreceptor cells of the snapping turtle pineal body were generally similar in fine structure to those of other lower verterbrates reported previously, and suggested to have both photoreceptive and secretory functions which were modulated by pinealofugal and pinealopedal nerves. The supportive cells were characterized by having large dense granules($0.3{\sim}1{\mu}m$), abundant ribosomes, well developed Golgi apparatus and rough endoplasmic reticulum. These cells were furnished with microvilli on the luminal cell surfaces, and often had centrioles, striated rootlets, abundant filaments especially around the nucleus, and scattered microtubules. Some supportive cells had cell body close to the lumen and extended a long process reaching to basal lamina, which appeared to be a glial cell. Nerve cells within the parenchyma were difficult to identify, but some large cells located basally were suspected to be nerve cells, since they had synaptic ribbon contact with photoreceptor cells.

• 한국과학교육학회지
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• 제18권3호
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• pp.273-282
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• 1998

학습 초기에 과학적 개념과 상충되는 오개념을 이용하여 인지 갈등을 일으킴으로써 개념 변화를 꾀하는 갈등유발집단과 과학적 개념과 어느정도 일치하는 부분과학개념을 이용하여 과학적 개념과 연결시켜줌으로써 개념 변화를 꾀하는 비갈등집단의 개념 형성 정도 및 지속효과를 비교하였다. 초등학교 5 6 학년을 대상으로 일상 생활에서 쉽게 접할 수 있는 열전도, 열평형, 작용 반작용, 자유낙하, 무게보존 등에 관한 기초적인 5가지 개념을 이용하였다. 갈등유발집단에게는 오개념을 가지고 답하리라 예상되는 문항을 제시하였으며, 비갈등집단에게는 과학적개념과 어느 정도 일치하는 부분과학개념을 가지고 답하리라 예상되는 문항을 제시하였다. 그 다음, 시범 실험을 실시하여 갈등유발집단은 오개념을 드러내어 갈등이 일어나게 하였으며, 비갈등집단은 부분과학개념을 이끌어내어 갈등이 일어나지 않고 과학적 개념과 연결시킬 수 있게 하였다. 두 집단 모두 설명식의 간단한 처치를 동일하게 실시하였으며 처치 직후와 일주후, 한달후에 사후 검사를 실시하여 개념의 형성 정도 및 지속 효과를 비교하였다. 기초적인 5가지 개념에 대해 갈등과 비갈등의 효과를 비교해 본 결과 열평형 개념과 작용 반작용 개념에서 갈등유발집단에 더 효과적인 결과를 얻었다. 그리고 학업성적을 통한 상위 수준과 하위 수준의 학생들을 비교하였을 때 상위 수준의 학생들은 열전도와 열평형 개념에서 갈등을 일으킨 다음 갈등을 해소해 주는 방법이 더 효과적이었으며, 하위 수준의 학생들은 갈등의 방법이나 비갈등의 방법이나 개념의 형성 정도나 지속 효과면에서 차이가 나타나지 않았다. 전체적으로 초등학생들에게서는 두 방법간에 뚜렷한 경향성은 나타나지 않았으나, 개념과 학습자의 특성에 따라 다양한 결과가 나타났다. 따라서 학습할 개념의 특성, 학생의 선개념 상태, 학습에서의 성공 경험에 따라 적절한 방법을 사용하여야 한다고 본다.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2292-2314
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• 2006

Efficient numerical method is developed for the prediction of aerodynamic noise generation and propagation in low Mach number flows such as aeolian tone noise. The proposed numerical method is based on acoustic/viscous splitting techniques of which acoustic solvers use simplified linearised Euler equations, full linearised Euler equations and nonlinear perturbation equations as acoustic governing equations. All of acoustic equations are forced with immersed surface dipole model which is developed for the efficient computation of aerodynamic noise generation and propagation in low Mach number flows in which dipole source, originating from unsteady pressure fluctuation on a solid surface, is known to be more efficient than quadrupole sources. Multi-scale overset grid technique is also utilized to resolve the complex geometries. Initially, aeolian tone from single cylinder is considered to examine the effects that the immersed surface dipole models combined with the different acoustic governing equations have on the overall accuracy of the method. Then, the current numerical method is applied to the simulation of the aeolian tones from twin cylinders aligned perpendicularly to the mean flow and separated 3 diameters between their centers. In this configuration, symmetric vortices are shed from twin cylinders, which leads to the anti-phase of the lift dipoles and the in-phase of the drag dipoles. Due to these phase differences, the directivity of the fluctuating pressure from the lift dipoles shows the comparable magnitude with that from the drag dipoles at 10 diameters apart from the origin. However, the directivity at 100 diameters shows that the lift-dipole originated noise has larger magnitude than, but still comparable to, that of the drag-dipole one. Comparison of the numerical results with and without mean flow effects on the acoustic wave emphasizes the effects of the sheared background flows around the cylinders on the propagating acoustic waves, which is not generally considered by the classic acoustic analogy methods. Through the comparison of the results using the immersed surface dipole models with those using point sources, it is demonstrated that the current methods can allow for the complex interactions between the acoustic wave and the solid wall and the effects of the mean flow on the acoustic waves.

• 화약ㆍ발파
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• 제22권1호
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• pp.33-43
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• 2004

본 연구에서는 철근콘크리트(reinforced connote) 구조물에 대해 발파해체 축소모형실험을 수행하고 이를 전산실험결과와 비교하였다. 적용된 발파해체 공법은 파괴거동을 비교적 쉽게 확인할 수 있는 점진붕괴공법이며, 차원해석(Hobbs(1969))을 실시하여 축소모형실험에 적용될 강도특성을 계산하였다. 이에 따라 석고, 모래, 물의 혼합하여 콘크리트를 대용할 재료로 사용하였으며, 연성을 지니며 축소강도가 철근과 유사한 땜용 납선을 철근 대용 재료로 사용하였다. 이 때 모래와 석고의 중량 비를 다양하게 변화시키면서 이에 따른 강도의 변화를 측정하고 최적의 강도 값을 갖는 배합 비를 결정하여 사용하였다. 모형의 제작은 실내에서 미리 양생된 부재들을 현장으로 옮겨 연결부만을 타설하여 일체화시키는 방법으로 구조물을 축조하였다. 축소모형실험을 전산실험결과와 비교하기 위하여 요소의 파괴거동을 육안으로 확인할 수 있는 개별요소법에 의해 수행되는 상용코드인 PFC2D(Particle Flow Code 2-Dimension)를 사용하여 전산해석을 수행하였다. 먼저 3차원 무근 콘크리트 라멘 구조의 모형을 설계하고 그 축소모형을 발파해체하여 거동을 촬영하였다. 이를 전산실험결과와 비교하여 2차원 해석의 한계는 존재하나 대체로 유사한 형태의 거동을 보임을 알 수 있었다. 그리고, 무근 콘크리트 라멘 구조 해석의 경험과 철근콘크리트 보의 실내 굴곡실험결과를 근거로 하여 철근콘크리트 구조모형의 발파해체 사전해석을 실시하였다. 그 결과, 2차원 해석이라는 한계에도 불구하고 900ms 까지는 거의 유사한 거동을 보이며 붕괴됨을 확인하였다.

• 대한수학교육학회지:수학교육학연구
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• 제23권2호
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• pp.253-267
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• 2013

본 연구는 학생들의 성취도 수준에 따라 구성된 동질 집단과 이질 집단에서 넓이 구하기 활동 중 나타나는 수학적 의사소통의 양태와 유추적 사고 과정을 분석함으로써 소집단내 의사소통이 유추적 사고 과정에 미치는 영향을 알아보는 것을 목적으로 하였다. 그 결과 동질 상위 집단은 개인 간 유사한 사고로 인해 의사소통의 필요를 느끼지 못하는 반면, 동질 중위 집단이나 하위 집단에서는 개인의 사고가 확장됨에 따라 의사소통이 점점 활발하게 일어났다. 이질집단의 경우는 상위권 학생이 의사소통을 주도해 감에 따라 하위권 학생의 참여횟수는 감소하였다. 그리고 평행사변형의 넓이를 구하는 활동(1차시 수업)으로부터 사다리꼴의 넓이를 구하는 활동(2차시 수업)으로 어떻게 유추가 일어날 수 있는지 그 사고 과정을 분석한 결과 소집단내 의사소통은 다른 학생들의 유추적 사고를 유발하며 그로인해 Rattermann의 유비추론 사고 과정 단계를 확장해 가는 것을 확인할 수 있었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1617-1617
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• 2001

It is well known now that near infrared spectroscopy (NIRS) is a fast, no destructive, and inexpensive analytical technique that could be used to classify, identify, and authenticate a wide range of foods and food items. Therefore, the main aims of this study were to provide a new insight into the authentication of five strawberry (Fragaria x ananassa) varieties and to correlate them with geographical zones and the propagating methods used. Three weeks plants of five different strawberry varieties (F. x ananassa Duch. cv Camarosa, Seascape, Chandler, F. Chiloensis, and F. Virginiana) were cultivated in vitro first and then transferred to pots with special soil, and grown in a greenhouse at CINVESTAV, all varieties were acquired from California (USA). After 18 months, ten leaves from each variety were collected. Transmission spectra from each leave were recorded over a range of 10, 000-4, 000 cm$-^{1}$, 32 scans of each strawberry leave were collected using a resolution of 4 cm$-^{1}$ with a Paragon IdentiCheck FT-NIR System Spectrometer. Triplicates of each strawberry leave were used. All spectra were analyzed using principal component analysis (PCA) and soft independent modeling class analogy (SIMCA). The optimum number of components to be used in the regression was automatically determined by the software. Camarosa was the only variety grown from the same shoot but propagated by a different method (direct or in vitro). Five different classes (varieties) or clusters were observed among samples, however, larger inter class distances were presented by the two wildtype samples (F. Chiloensis and F. Virginiana). Camarosa direct and Camarosa in vitro displayed a small overlapping region between them. On the other hand, Seascape variety presented the smallest rejection percentage among all varieties (more similarities with the rest of the samples). Therefore, it can be concluded that the application of NIRS technique allowed the authentication of all strawberry varieties and geographical origin as well. It was also possible to form subclasses of the same materials. The results presented here demonstrate that NIRS is a very powerful and promising analytical tool since all materials were authenticated and classified based on their variety, origin, and treatment. This is of a tremendous relevance since the variety and origin of a plant material can be established even before it gives its typical fruit or flower.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1257-1257
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• 2001

Fourier transform near infrared (FT-NIR) spectroscopy was used as a rapid method to measure the $^{o}Brix$ content and to discriminate between different must samples in terms of their fee amino nitrogen (FAN) values. FT-NIR spectroscopy was also used as a rapid method to discriminate between Chardonnay wine samples in terms of the status of the male-lactic fermentation (MLF). This was done by monitoring the conversion of malic to lactic acid and thereby determining whether MLF has started, is underway or has been completed followed by classification of the samples. Furthermore, FT-NIR spectroscopy was applied as a rapid method to discriminate between table wine samples in terms of the ethyl carbamate (EC) content. EC in wine can pose a health threat and need to be monitored by determining the EC content in relation to the regulatory limits set by the authorities. For each of the above mentioned parameters, $QUANT+^{TM}$ methods were built and calibrations derived and it was found that a very strong correlation existed in the sample set for the FT-NIR spectroscopic predictions of $^{o}Brix$ (r = 0.99, SECV = 0.306), but the correlations for the FAN (r = 0.61, SECV = 272.1), malic acid (r = 0.58, SECV = 1.06), lactic acid (r = 0.51, SECV = 1.14) and EC predictions (r = 0.47, SECV = 3.67) were not as good. Soft Independent Modeling by Class Analogy (SIMCA) diagnostics and validation was applied as a sophisticated discrimination method. The must samples could be classified in terms of their FAN values when SIMCA was applied, obtaining results with recognition rates exceeding 80%. When SIMCA diagnostics and validation were applied to determine the progress of conversion of malic to lactic acid and the EC content, again results with recognition rates exceeding 80% were obtained. The evaluation of the applicability of FT-NIR spectroscopy measurement of FAN, $^{o}Brix$ values, malic acid, lactic acid and EC content in must and wine shows considerable promise. FT-NIR spectroscopy has the potential to reduce the analytical times considerably in a range of measurements commonly used during the wine making process. Where conventional FT-NIR calibrations are not effective, SIMCA methods can be used as a discriminative method for rapid classification of samples. SIMCA can replace expensive, time-consuming, quantitative analytical methods, if not completely, at least to some extent, because in many processes it is only needed to know whether a specific cut off point has been reach or not or whether a sample belongs to a certain class or not.

• 한국실내디자인학회논문집
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• 제18권5호
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• pp.111-118
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• 2009

Urban houses of traditional Korean Style are a type of habitation that happened during a transitional period when the modernization of habitation had progressed in 1930s, and also a habitation folding societal trails that had adapted and developed into urbanization together with the native traits of traditional Korean Style houses. Because they keep our style of living and the process of change just as they were, it is important work to shed light on and keep a record of it. So, this thesis arranges the contents of research on the actual condition of living, and may try to reason by analogy the changing style of residents' living through the change of space composition and the way of space usage for the urban houses of traditional Korean style that were changed by extension and remodeling of residents. As the concrete matters, it is to grasp the physical and spatial change of urban houses of traditional Korean style in accordance with extension and remodeling, and to analyze in which part and how they had been changing for the spatial composition of urban houses of traditional Korean style according to the change of living style, and especially the change toward a stand-up type of k stand-and the following traits and factors of the change toward Dining-Kitchen. The kitchen changed toward Dining-Kitchen shows some typical discrepancies depending on the location of kitchen as like a case of changing toward Dining-Kitchen from the existing location, a case of extending into the rear side of kitchen, a case of switching of location between kitchen and the inner room, and a case of changing toward Dining-Kitchen from the location of a room across from the main living room. As kitchen changed toward Dining-Kitchen like these, it shows that the connecting trace into the inner room came out, each room came to show a bit clearer function but grow smaller relation with the threshing ground, and also the function of the threshing ground came reduced.

• 복식
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• 제55권4호
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• pp.62-78
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• 2005

The modern period was the time that the most radical and extensive social and mental changes were occurring throughout the history, and modernism was prevailing as a general cognition system of people. Modernism, which carries principles of progress, belief in application of scientific technology, worship of reason, ideal of liberty as a col-e value of civilization, was plated as a leading ideology in the realm of society, culture and art In the early 20th century. In this study, the formative characteristics of modernism seen in architecture and fashion are analogized and analyzed in four ways ell the basis of the theory of p. Greenhalgh. First, 'Standardization for mass-production', which is analogized which P. Greenhalgh's 'Decompart-mentalisation', 'Social Morality', and' Technology'. Standardization for mass-production in architecture focuses on the development of a design prototype in order to mass produce; the development of ready-made clothes is actively done ill the fashion area for the same purpose as well. Second, 'Rational functionality' coming from P. Greenhalgh's 'The total work of art' and 'Function'. While rational functionality in architecture puts an emphasis on the rational operation of all the functions in regard to the relation between each part and the whole, rational functionality in fashion call be mainly seen in a dramatic increase in physical activity which could be hardly found before the modernism period. Namely, all the fashion design elements are developed for a certain rational and functional design on each part as well as on the whole in order to greatly increase physical activity. Third, 'the pursuit for genuineness of objects and universality of beauty' is on the analogy of P Greenhalgh's 'Truth', 'Anti-historicism', 'Abstraction', 'Internationalism/Universality'. This idea is adopted in architecture in the form of design of geometrical abstraction. In the same way, design using geometrical abstraction comes to have a significant meaning in fashion of the modernism period. So to speak, modernism architecture and fashion can be reborn to become an inter·national style by giving up the decorative and regional design prevailing before modernism and by expressing universal aesthetics in the form of simplicity and abstraction instead. Fourth, 'Expression of progress through a change in a viewpoint' stems from P. Greenhalgh's 'Progress', 'Transformation of Consciousness', 'Theology'. In architecture, this concept appears by using new construction materials and methods and by representing new aesthetical idea. As a result, it makes it possible for people to make progress for better lives. Like in architecture, new attempts for material application and processing are made in fashion. This gives rise to a general change in a viewpoint related to fashion, so that a flew fashion design which there has never been before can come out.

• 한국학교수학회논문집
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• 제15권3호
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• pp.535-563
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• 2012

본 연구는 유추 조건에 따른 수학적 문제 해결 양상을 분석하여 유추적 사고의 필요성을 확인하고, 시각적 표상을 통한 유추의 효과를 경험적으로 검증하기 위하여 실시되었다. 이러한 목적을 달성하기 위하여 충청북도 청주시에 소재한 일반계 고등학교인 C고등학교 3학년 학생 80명을 연구 대상자로 선정하였다. 이들은 유추 상황에 따라 설정된 표상 대응 조건, 개념 대응 조건, 탐색 조건과 비 유추조건인 단순조건에 각각 20명씩 배정되었으며, 1차 실험과 2차 실험에서 각 조건에 따라 서로 다른 학습 자극을 받은 후에 복소수 수열과 관련된 동일한 문제를 풀었다. SPSS 12.0을 이용한 ${\chi}^2$ 분석을 토대로 유추 조건에 따른 문제 해결률을 비교하여 분석한 결과, 수학적 문제 해결 과정에서 유추적 사고가 이루어지지 않을 경우에 이미 알고 있는 바탕 지식의 사용이 제한될 수 있으며, 시각적 표상을 통하여 바탕 개념과 표적 개념을 대응시켜 보는 것이 유추 전이에 효과적이라는 것을 확인할 수 있었다. 이와 같은 결과는 문제 해결 과정에서 유추적 사고의 필요성을 함의하고 있으며, 시각적 표상을 통하여 바탕 개념과 표적 개념의 관계적 유사성을 인식하는 것이 수학적 문제 해결과 밀접하게 관련되어 있다는 주장을 지지하는 경험적인 근거가 된다.