• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.90-93
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• 2009

물리기반 형상변형 기술은 게임 및 시뮬레이션과 같은 분야를 중심으로 점차 그 사용이 증가하는 추세이고 이에 대한 다양한 연구가 이루어지고 있다. 하지만 아직까지 3 차원 객체와 물리기반 변형기술간의 상호작용을 증대시키기 위한 연구는 원활이 이루어지지 않고 있다. 본 연구는 사용자의 몰입감을 증가시키고 변형의 효율성을 높이기 위해서 증강현실 환경을 이용한 물리기반 형상변형을 제안한다. 증강현실 환경 하의 시스템에서 3 차원 객체와 사용자의 효율적인 상호작용을 위해서는 물리기반 형상변형이 실시간으로 이루어져야 한다. 제안된 방법에서는, RBF(Radial Basis Function) [1] 와 LSM (Lattice Shape Matching) [2, 3]방법을 조합해서 메쉬 모델에 적용하였다. 또한, 물리기반 형상변형을 위해 lattice shape matching 의 동적 움직임을 계산하였다. 최종적으로, 이러한 방법들을 증강현실 환경 하에서 구현하였다.

• 대한세포병리학회지
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• 제15권1호
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• pp.65-69
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• 2004

Epithelioid sarcoma is a malignant soft tissue neoplasm with an uncertain histogenesis. We report the imprint cytologic features of epithelioid sarcoma in the left shoulder of a 29-year-old male patient. Imprint cytologic findings showed dissociated and loose aggregates of anaplastic epithelioid cells on the necrotic, bloody, and inflammatory background. Tumor cells were round to polygonal shaped. Tumor cells had vesicular nuclei with abundant cytoplasm. The nuclei were irregular in shape and often eccentrically located. Some tumor cells were oval to spindle shaped. Binucleated and multinucleated cells were found. Intracytoplasmic vacuoles were present. On immunohistochemical stain, the tumor cells were positive for epithelial membrane antigen, vimentin, and CD34.

• 환경생물
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• 제37권3호
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• pp.293-298
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• 2019

A marine ulvalean species (Chlorophyta) was collected from the eastern coast of Korea. This species is morphologically characterized by a distromatic, dark to medium green and mostly irregularly orbicular or irregularly expanded thallus with entire or undulate margin without serrations. Vegetative cells are irregularly polygonal with distinctly rounded corners in shape, and have chloroplast completely covering the outer cell wall and one to two pyrenoids per cell. In a phylogenetic tree based on ITS (Internal Transcribed Spacer) sequences, this Korean alga nests in the same clade with Ulva sublittoralis, as a sister clade of U. californica, U. flexuosa and U. tanneri, which share the irregularly orbicular or expanded thallus normally without teeth cells. The genetic divergence between them is intraspecific within Ulva. Accordingly, it is identified as U. sublittoralis based on the morphological and molecular data. This is the first record of Ulva sublittoralis in the Korean marine algal flora.

• Computers and Concrete
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• 제10권5호
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• pp.541-555
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• 2012

This paper presents an algorithm for the evaluation of stresses in reinforced concrete sections under service loads. The algorithm is applicable to any section defined by polygonal contours and is based on an analytical integration of the stresses. The nonlinear behaviour of concrete is represented by the parabola-rectangle law used in the Eurocode-2 for the ultimate concrete design. An integrated definition of the strains in concrete and steel is possible by the use of Heaviside functions, similarly to what is done for ultimate section design in Barros et al. (2004). Other constitutive equations for the definition of the stresses in the concrete or steel can be easily incorporated into the code. The examples presented consist in the evaluation of resulting axial load and bending moment in an irregular section and in a section in L shape. The results, for service stresses, can also be plotted in terms of design abacus; a rectangular doubly reinforced section is presented as example.

• Ocean Systems Engineering
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• 제2권1호
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• pp.69-81
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• 2012

Presented herein is a study on reducing the hydroelastic response of very large floating structures (VLFS) by altering their plan shapes. Two different categories of VLFS geometries are considered. The first category comprises longish VLFSs with different fore/aft end shapes but keeping their aspect ratios constant. The second category comprises various polygonal VLFS plan shapes that are confined within a square boundary or a circle. For the hydroelastic analysis, the water is modeled as an ideal fluid and its motion is assumed to be irrotational so that a velocity potential exists. The VLFS is modeled as a plate by adopting the Mindlin plate theory. The VLFS is assumed to be placed in a channel or river so that only the head sea condition is considered. The results show that the hydroleastic response of the VLFS could be significantly reduced by altering its plan shape.

• Journal of Ginseng Research
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• 제5권2호
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• pp.114-121
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• 1981

Starch was isolated from 4-year-old and 6-year-old ginseng roots and its physical and chemical characteristics were studied. The results obtained were summarized as follows. 1. The shape of ginseng starch granules was polygonal and rounded with its granule size ranging from 2.0 to 7.5$\mu$. The swelling power of 4-year-old ginseng starch was much greater than that of 6-year old ginseng starch. Gelatinization pattern showed that 6-year-old ginseng starch gelatinized rapidly at $65^{\circ}C$, whereas 4-year-old starch continued to gelatinize, without having a definite gelatinization temperature as temperature increased 3. Amylogram of ginseng starch showed that gelatinization initiated at 61$^{\circ}C$ and was completed at 88$^{\circ}C$ with its viscosity reaching at 810 B.U. 4. The amylose contents were 32% and 9% for 4-year-old and 6-year-old ginseng starch, respectively. 5. X-ray diffraction analyses indicated that there were some structural differences between 4-year-old and 6-year-old ginseng starch.

• 한국정밀공학회지
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• 제15권6호
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• pp.175-182
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• 1998

An advanced visual tracking and stable grasping algorithm for a moving object is proposed. The stable grasping points for a moving 2D polygonal object are obtained through the visual tracking system with the Kalman filter and image prediction technique. The accuracy and efficiency are improved more than any other prediction algorithms for the tracking of an object. In the processing of a visual tracking. the shape predictors construct the parameterized family and grasp planner find the grasping points of unknown object through the geometric properties of the parameterized family. This algorithm conducts a process of ‘stable grasping and real time tracking’.

• 융합신호처리학회논문지
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• 제14권4호
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• pp.212-216
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• 2013

As virtual reality technologies are advanced rapidly, how to render 3D objects across modalities is becoming an important issue. This study is therefore aimed to investigate human discriminability on the curvature of 3D polygonal surfaces with focusing on the vision and touch senses because they are most dominant when explore 3D shapes. For the study, we designed a psychophysical experiment using signal detection theory to determine curvature discrimination for three conditions: haptic only, visual only, and both haptic and visual. The results show that there is no statistically significant difference among the conditions although the threshold in the haptic condition is the lowest. The results also indicate that rendering using both visual and haptic channels could degrade the performance of discrimination on a 3D global shape. These results must be considered when a multimodal rendering system is designed in near future.

• 전자공학회논문지B
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• 제31B권8호
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• pp.119-128
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• 1994

In this paper we propose a new method for the recognition of 2-D partially occluded objects. The border of the object is transformed to a curve in arc length-accumulated interior angle plane. The transformed curve of an image is partitioned so that each segment is bounded by the concave interior angles. In order to tolerate shape distortion due to the polygonal approximation of the boundary of the object a group of feature points of the input image are matched with those of model views. The estimation method for positions and orientations of the identified objects objects is presented.

• 한국CDE학회논문집
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• 제10권5호
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• pp.339-348
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• 2005

In this paper, LOD (Level Of Detail) for flocking, which is the real-time simulation on the movement or some groups such as fighting soldiers, moving fishes and flying birds, is presented. And a flocking LOD algorithm that uses factors such as the speed of fish, direction, and shape is proposed. Model data is modified for LOD in advance, so as to reduce strange edge collapse and unwanted holes. The errors of model data were identified by transforming polygonal model into octree-based cubes and revised before rendering. Experimental results show that the proposed algorithm considering flocking characteristics shows fast frame rates as compared with the conventional continuous LOD algorithm.