• Journal of Korean Library and Information Science Society
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• v.9
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• pp.115-144
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• 1982

In ordinary modern wester expression 'the Renaissance' was used to denote the impact made by dead Hellenism civilization in western Christendom, particularly Italian literary and artistic movement at Northern and central Italy in the late medieval period. However, A.J. Toynbee examined the renaissance from the different aspect of view. In his great work "A Study of History" in vol. IX, he succeeded in establishing the theory of historic civilization encounters in space and in time; and in time, civilization of the present and the past or between dead and infant successor contacts on the analogy of parenthood and sonship in the relation of A n.0, pparentation-and-Affiliation. The distinguished his view of 'Renaissance' was illustrated in the sense of encounters between a grown-up civilization and the 'ghost' of its long-dead predecessor. The renaissances (by the process of evocation of ghost of its parent society) has not only one single aspect of literary and artistic field but also in politics, law, science and philosophy, languages and literatures and visual arts, and religion. The main theme of this study is to examine the development of libraries and its historical meaning through Toynbee's literary renaissance. His renaissance of Languages and Literatures has three typical steps: They are: 1st step-to restive the dead literature's remains: 2nd step-to remaster their meaning: 3rd step-to reproduce them in counterfeits... Through its first and second steps, collecting and editing, annotating by compiling an anthology, thesaurus, lexicon or encyclopedia, and in its third step publishing mostly imitation of classics took place. Toynbee depicted the five outstanding eminent representatives of literary renaissance who had a n.0, ppeared on the state of history down to the time of writing. They are: Assurbanipal, Constantine prophyrogenitus, Yung Lo, K'ang Hsi, and Ch'ien Lung and the last four had all been emperors of imperia rediviva. As the result of the examination of these five emperors with three steps of literary renaissance, the common result may be summarized as follows: 1. Those emperors of imperia rediviva interested in intellectual work and study, they also were deeply involved in collecting classics in an ostensible reason. 2. There were strong political intention of collecting materials as an a n.0, ppeasement policy of civilization by transferring scholars energies to an intellectual field. 3. Under the rulers of a resuscitated universal state, the literary renaissance were a product of political plane and that the total size of collection and work were huge. 4. Since there were strong exercise of sovereign power, an active censorship by distortion and elimination was inevitable. 5. There existed newly developed strained atmosphere between grown-up and long-dead parent civilization, whenever the book collection movement had occurred. 6. Over adhesion to the parent civilization caused imitation of classic work and the creative activities were stagnated.stagnated.

• Journal of the Korea Computer Graphics Society
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• v.8 no.2
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• pp.1-7
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• 2002

The fast extraction of the silhouettes of a model is very useful for many applications in computer graphics and animation. In this paper, we present an efficient algorithm to compute a sequence of perspective silhouettes for a polyhedral model from a moving viewpoint. The viewpoint is assumed to move along a trajectory q(t), which is a space curve of a time parameter t. Then, we can compute the time-intervals for each edge of the model to be contained in the silhouette by two major computations: (i) intersecting q(t) with two planes and (ii) a number of dot products. If q(t) is a curve of degree n, then there are at most of n + 1 time-intervals for an edge to be in a silhouette. For each time point $t_i$ we can extract silhouette edges by searching the intervals containing $t_i$ among the computed intervals. For the efficient search, we propose two kinds of data structures for storing the intervals: an interval tree and an array. Our algorithm can be easily extended to compute the parallel silhouettes with minor modifications.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.120-130
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• 2009

This study focuses on the methodology of an ecological interpretation of Korean traditional landscapes through both life-oriented philosophy and traditional Korean philosophy which are similar to ecology. Also, useful tools for discovering an ecological technique of formation based on the ecological thoughts in ancestors' life are shown. Ecological key words as interpretative tools on the traditional landscape replaced ecological concepts in Korean culture and landscape. There are 'Bonsung(本性; the original nature)', 'Chungjeol(中絶; moderation)', 'Hyoyul(效率; efficiency)', 'Sangsaeng(相生; symbiosis)', 'Jasaeng(自生; self-generation)', 'Chunghwa(中和; neutralization)', 'Bangtong(旁通; communication)', and 'Byuntong(變通; variableness)'. For the case study, the concepts of 'spatial structure', 'constructive elements in the traditional gardens', and 'structural elements in the dwelling houses' were extracted from $\ulcorner$Imwonkyeongjeji$\lrcorner$ as an interpretative subject. As a result, Jeongon house, Jongtaek of Choi's family(the first incoming resident) showed us an ecological technique of formation by interpretation on the composing elements. Namely, they are natural dwelling houses in harmony with natural conditions and delicate relational styles. Five kinds of ecological characteristics were exposed. They are: 1. land use method following natural features('本性' '相生' '中和'), 2. physical and spatial elements in a body with nature('中絶' '相生' '中和'), 3. sustainable circulation system by recycling limited resources('效率' '自生' '旁通'), 4. use of natural materials based on the regional climate ('中絶' '效率' '自生') and 5. plane and structural decision by microclimate('效率' '自生' '變通'). Consequently, the dwelling houses and their traditional gardens aimed at the consuming space of the efficient resources by utilizing and circulating natural energy more than different types of the traditional spaces.

• Composites Research
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• v.32 no.6
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• pp.395-402
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• 2019

The RFI process is an OoA process that fiber mats and resin films are laminated and cured in a vacuum bag. In case that resin film is insufficient to fill empty space in fibers, it makes void defect in composites and this void decrease mechanical properties of the composites. For this reason, non-destructive testing is usually used to evaluate void of manufactured composites. So, in this study, a manufacturing method of standard void specimens, which are able to be used as references in non-destructive testing, was proposed by controlling resin film thickness in the RFI process. Also, a fiber compaction test was proposed as a method to set the resin film thicknesses depending on target voids of manufacturing panels. The target void panels of 0%, 2%, and 4% were made by the proposed methods, and signal attenuation depending on void was measured by non-destructive testing and image analysis. In addition, voids of specimens for tensile, in-plane, short beam and compressive tests were estimated by signal attenuation, and mechanical properties were evaluated depending on the voids.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.603-606
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• 1991

The crystal structure of Probenecid has been determined from 2574 independent reflections collected on an automatic ENRAF-NONIUS CAD-4 diffractometer using graphite-monochromated $Mo-K{\alpa}$ radiation. The crystal is triclinic, space group P$\bar{1}$ with unit cell dimensions a = 7.535(2)${\AA}$, b = 18.473 (5)${\AA}$, c = 5.317(9)${\AA}$, ${\alpha} = 92.00(5)^{\circ}$, ${\beta} = 99.02(5)^{\circ}$, ${\gamma} = 94.89(2)^{\circ}$, V = 727.4(2)${\AA}^3$, Z = 2, $D_m$ = 1.310, $D_x$ = $1.302 gcm^{-3}$, ${\mu}$ = $1.88 cm^{-1}$, F(000) = 304, and T = 298 K. Final R = 0.0676 and $R_w$ = O.0630 for 1209 reflections > 5${\sigma}(F_o)$. In the spacial arrangement about N(13), the sum of bond angles about nitrogen is 350.9° and the nitrogen lies only 0.268(6)${\AA}$ out of S(1)-C(14)-C(17) plane. The S(1)-C(4) distance is 1.792(6)${\AA}$ and the C(4)-S(1)-N(13) angle is $106.5(3)^{\circ}$. The overall conformation of the molecule is folded with respect to sulfur.

• Journal of the Korean Chemical Society
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• v.38 no.5
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• pp.339-344
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• 1994

The crystal structure of a methanol sorption complex of dehydrated partially Co(II)-exchanged zeolite A, $Co_4Na_4-A{\cdot}6.5CH_3OH$ (a = 12.169(1) $\AA)$, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Pm$\bar3$m at $21(1)^{\circ}C. $Co_4Na_4$-A was dehydrated at $360^{\circ}C\;and\;2{\times}10^{-6}$ torr for 2 days, followed by exposure to about 104 torr of methanol vapor at $22(1)^{\circ}C$ for 1 hr. The structure was refined to final error indices, $R_1$ = 0.061 and $R_2$ = 0.060 with 147 reflections, for which I > $3\sigma(I).$ In this structure, four $Co^{2+}$ ions and 1.5 $Na^+$ ions per unit cell lie at 6-ring positions: the $Na^+$ ions are recessed 0.44 $\AA$ into the sodalite unit and the Co(II) ions extend ca. 0.55 $\AA$ into the large cavity. 2.5 $Na^+$ ions lie in an 8-oxygen ring plane. The 6.5 methanol molecules are sorbed per unit cell. The 6.5 methanol oxygens, all in the large cavity, associate with the 4 $Co^{2+}$ ions and 2.5 $Na^+$ ions.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.320-328
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• 2000

The numerical simulation of Brazilian fracture toughness test is carried out using PFC code and the influence parameters are analyzed such as shape of loading plane, size of Brazilian disc and unit particle of model, loading angle and loading rate. The flattened Brazilian disc is adopted for applying uniform load. The range of loading angle(2$\alpha$) necessary to induce the tensile crack at disc center and to obtain the load-displacement curve giving the critical load for the stable crack propagation is shown as 20°∼40°. In condition that the loading angle is 20°, the mode-I fracture toughness is evaluated almost constant in the range of particle size less than 1 mm and loading rate less than 0.01㎜/s. This range of influence parameters seems appropriate condition for the tensile crack initiation at disc center and the control of stable crack propagation, which can give the reliance in evaluation of fracture toughness by Brazilian test.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.132-139
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• 2015

Visual SLAM(Simultaneous Localization And Mapping) has been used widely to estimate a mobile robot's location. Visual SLAM estimates relative motions with static visual features over image sequence. Because visual SLAM methods assume generally static features in the environment, we cannot obtain precise results in dynamic situation including many moving objects: cars and human beings. This paper presents a stereo vision based SLAM method in dynamic environment. First, we extract disparity map with stereo vision and compute optical flow. We then compute disparity change that is the estimated flow field between stereo views. After examining the disparity change value, we detect ROIs(Region Of Interest) in disparity space to determine dynamic scene objects. In indoor environment, many structural planes like walls may be determined as false dynamic elements. To solve this problem, we segment the scene into planar structure. More specifically, disparity values by the stereo vision are projected to X-Z plane and we employ Hough transform to determine planes. In final step, we remove ROIs nearby the walls and discriminate static scene elements in indoor environment. The experimental results show that the proposed method can obtain stable performance in dynamic environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1325-1333
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• 2014

The dispersion pattern of a near miss neutralizer has a great effect on the disablement of a threatening projectile. This study numerically investigated the dispersion pattern of cylindrical tungsten impactors by an explosion in the near miss neutralizer. The mass and shape of the explosive were considered as influencing factors on the dispersion pattern. The explosives were set using two shape models: a parallel shape with the same upper and lower thicknesses and a tapered shape with different upper and lower thicknesses. In the simulation results, the dispersed impactors formed a ring-shaped pattern on a two-dimensional plane in an arbitrary space. In addition, the fire net area increased with the explosive mass when the explosive shapes were identical. In particular, the tapered shape explosive formed a larger fire net area than the parallel shape explosive. Based on the analysis of the fire net area along with the dispersion density, both the explosive mass and shape representing the physical characteristics should be considered for controlling the dispersion pattern of impactors in a near miss neutralizer.

• The korean journal of orthodontics
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• v.35 no.5 s.112
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• pp.388-397
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• 2005

The purpose of this study was to redefine the cephalometric landmarks in three-dimensional (3D) images, which are used in orthodontic cephalometric radiography, and to evaluate the reproducibility of each landmark for 3D cephalometric analysis. Eighteen CT scans were taken at the Department of Diagnostic Radiology at Seoul National University Dental Hospital and manipulated with V works 4.0(Cybermed Inc., Seoul, Korea). The coordinate system was established using 7 reference points, with no more than 4 points on the same plane. These 7 points were generated as a volume model, the voxel size of which was 4 by 4 by 2 (threshold value=639). The cephalometric landmarks were selected at the multiplanar reformation (MPR) window on the volume mode of V works 4.0. The selected landmarks were exported to V surgery (Cybermed Inc., Seoul, Korea) for the calculation of coordinate values. All the data were taken twice with a lapse of 2 weeks by one investigator The reproducibility of each landmark was $0.17\~1.21mm$ in the x axis, $0.30\~1.53mm$. In the y axis, and $0.27\~1.81mm$ in the z axis. In all three axes, the range of error was similar. These error ranges were acceptable with regards to the pixel space and slice thickness. The most reproducible points were 1 points which were selected on the basis of the volume model. The least reproducible points were J points that were defined by sutures.