• Communications of the Korean Mathematical Society
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• v.38 no.1
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• pp.47-53
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• 2023

The Terracini t-locus of an embedded variety X ⊂ ℙ^r is the set of all cardinality t subsets of the smooth part of X at which a certain differential drops rank, i.e., the union of the associated double points is linearly dependent. We give an easy to check criterion to exclude some sets from the Terracini loci. This criterion applies to tensors and partially symmetric tensors. We discuss the non-existence of codimension 1 Terracini t-loci when t is the generic X-rank.

• Journal of Korean Theatre Studies Association
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• no.40
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• pp.5-27
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• 2010

The Korean Mask-Dance Theatre has been developed closely related to Korean Shaman rituals. As many scholars noticed, the performers of the Mask-Dance Theatre were closely related to the Shaman family. In addition, there are mask-dance performances in actual shaman rituals. and are the representative performances among them. This essay intends to compare these two mask-dance performances in the shaman rituals to the similar performance of Old Grandpa and Grandma episode in the regional Mask-Dance Theatre. This study would bring us further in proving the close relation between the shaman ritual and the Mask-Dance Theatre. is one episode, Keori, in the shaman ritual of 'Baeyeonsin-kut' and 'Taedong-kut' in the mid-west seashore area. 'Taedong-kut' is the village shaman ritual for fertility and prosperity, while 'Baeyeonsin-kut' is a private shaman ritual for a large catch of the ship. is held in the later part of the whole shaman ritual since the later part tend to be more for entertainment than actual ritual. The story of is very similar that of in Pongsan Mask-Dance Theatre of the mid-west region. In addition, some of their dialogues are very similar. Only the later part is different. These similarities indicate that the Mask-Dance Theatre, which came into being in later period than the shaman ritual, has likely taken the story motif of the shaman ritual. is also a performance in the shaman ritual of east coasts. is more elaborate and recreational than of the west coasts. is also performed near the end of the ritual, and sometimes it is not performed at all. This indicates that has little ritual meaning left. When we compare it with the regional Mask-Dance Theatres such as Keosung Okwangdae, Tongyong Okwangdae, and Suyong Yaryu, the structure and the story lines are also very similar. It is a question why only the motif of the Grandpa and Grandma isfound both in the shaman ritual and the Mask-Dance Theatre. Many other motifs of other episodes in the Mask-Dance Theatre are not found in the shaman rituals. It seems that the Grandpa and Grandma motif is related to the ur-belief in fertility. In other words, this motif seems to be originated from the old belief in the fertility couple of Chonha Taechanggun and Jiha Yeochanggun. The shaman ritual for fertility first picked up this motif, and then the mask-dance theatre also adapted this motif for its recreational purpose. When we compare with , still has more aspects of fertility ritual, while lost its ritualistic meaning and its main purpose is to develop dramatic needs. and are invaluable existent performances to prove theatre's origin in ritual. The existence of mask-dance performances in the shaman rituals shows us the transit performance between theatre and ritual.

• Korean Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.93-102
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• 1997

Most design changes are due to interferences and fit-up as parts are assembled if such a large product as an automobile or an aircraft is developed by many concurrent engineers. In this part (1) of the thesis, the assembly-centric modeling methodology with CAD systems is proposed in order to reduce the design changes. Unlike part-centric modeling method, a part is modeled with its own coordinate system which is used in downstream process as machining and measuring. The part coordinates initially have the same orientation as its assembly which is predefined in BOM (Bill of Material). Then, the corrdinates origin of the part is moved to its location to be assembled from that of its assembly coordinate system. To implement this methodology, the position data of the part w.r.t. its assembly are stored in a database to build the same hierarchical assembling structure as BOM structure. This modeling approach has the advantage of reflecting asembling sequence, because the process of positioning parts is similar to that of real assembling. And with the method, a designer can easily adjust all of the part positions of an assembly to resolve interferences if he modifies just the coordinates origin of the assembly, which results in moving included parts and assemblies together.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.339-342
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• 1996

In this paper, the method for controlling PUMA robot using F/T sensor is described. In the part of the setup automation, robot is used. The F/T sensor is located at robot end-effector and various experiments are executed such as peg in hole, gripping objects, tool changing, etc.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.1
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• pp.1-8
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• 1993

In this paper, the surface roughness influenced by Sm45C hardness in high frequency induction hardening and mechanical characteristics for the changed Hv 598 part and the unchanged hardness Hv 223 part by use of cermet and ceramic cutting tools was experimentally examined. Finally, we could be had some important results by processing surface roughness on cutting conditions such as cutting speed, feed rate, depth of cut and changes of tool nose radius. The results are summarized as follows. 1. In case of the same cutting condition, the hardness of workpiece was high and acquired the best processing surface roughness when the radius of the tool nose had 0.8 mm and feed rate was 0.04 mm/rev. 2. In case of the hardness of workpiece, though the cutting speed didn't have an effect on processing surface roughness, the less feed rate and the more processing surface roughness improved. On the other hand, the low inside the hardness of workpiece, the more cutting speed and the more feed rate increase, the processing surface of roughness improved. 3. Regardless of the hardness of workpiece, the change of the cutting depth didn't have great effect on the surface roughness. 4. On cutting the high surface hardness part with cutting tools of cermet and ceramic, it can be acquired the higher processing surface roughness because it hadn't been taken effect on cutting speed, In case of the cutting process of the low inside hardness part the two cutting tools have acquired the similar processing surface roughness.

• Journal of the Korean Society of Costume
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• v.50
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• pp.5-22
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• 2000

The study on the past costume should be done first for the creation of new style of fashion. That is one of the reasons why we have to annalize characteristic style in each period. Before the latter of nineteenth century one must have made the costume by draping design. Because the complicated clothes can be expressed by draping deign think that the subject draping design is even more important than other subject. But there haven't been the studies that analyzed the pattern of Art Nouveau style by draping design in Korea. Art Nouveau style is a certain one that was relatively more changeable than the ones of other periods. The purpose of this study is the analysis about the patterns of hourglass and S-curve style which represented the Art Nouveau style. The results of the study summarized as follows. 1. Bodice pattern : In the front Hourglass silhouette has the princess line for fitting bodice while S-curve silhouette has the wide midriff due to the blousing. There is the yoke in S-curve one. In the pattern of back bodice we can't see the much differences but Hourglass silhouette is used the princess line like the front one while S-curve is made use of the waist darts for fitting back. 2. Sleeve pattern : Hourglass silhouette is made of two pieces the upper part and lower part besides S-curve is consisted of one pieces. The former has the big upper part in order to the emphasis of the shoulder and the tight lower part. The latter is the tight sleeve that similar to the basic sleeve pattern at present. 3. Skirt pattern: There is partially a gored line in the front skirt in Hourglass silhouette however S-curve silhouette is consisted of the six pieces gored skirt. At this part we can also see the fact that s-curve is more complicated than Hourglass silhouette. 4. Others: Wecan find out the differences between Hourglass and S-curve pattern easily at the parts of the collar flounce wing and so on. Summing up, the patterns of S-curve style are more expanded than those of Hourgalss style for the most part.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.187-192
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• 2022

This research focuses on analyzing the correlation between adolescent self-esteem and labor participation. The findings of this study are as follows: First, when it was analyzed whether there are differences in self-esteem with ages, out of school students were the lowest. and self-esteem level increased with age. Second, when the differences in self-esteem levels between genders were examined, male students showed slighty higher positive self-esteem and total self-esteem, which shows statistically significant difference. Third, the correlation between self-esteem and labor participation is as follows: 50.4% of students experienced part-time jobs in low self-esteem group. And 50.6% of students experienced part-time jobs in high self-esteem group. It shows that self-esteem level doesn't have relation to part-time job experience. Fourth, when the correlation between part-time job intention and self-esteem was analyzed, 50.5% of students in low self-esteem group responded they would have part-time job, but 49.5% of students in high self-esteem group. Also, 50.9% of low self-esteem group students responded they had no intention of getting part-time jobs, but 49.1% in high self-esteem group. It shows self-esteem level doesn't influence the decision to get part-time jobs. Last, the correlation between the reason they get part-time jobs and self-esteem level was analyzed. 68.1% of students in low self-esteem group had part-time jobs voluntarily, while 31.9% had to have jobs involuntarily for economic cause. Also 75.2% of students in high self-esteem group had part-time jobs for voluntary motive and 24.8% for economic cause. So high self-esteem group showed more voluntary cause and low involuntary cause for part-time jobs, but there was no statistically significant value.

• Broadcasting and Media Magazine
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• v.7 no.3
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• pp.44-53
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• 2002

본 논문은 현재 ITU-T와 ISO에 의해서 공동으로 표준화 작업이 진행되고 있는 H.26이 MPEG-4 Part 10표준의 변환(transform) 및 양자화(quantization) 과정에서 대해서 서술하는 것을 목적으로 하고 있다. H.26이 MPEG-4 Part 10 에서는 H.263, MPEG-4등과는 달리 H.26이 MPEG-4 Part 10 표준은 정수 변환(integer transform)을 채택함으로 인해서 구현시의 분해능(resolution)에 따라서 달라질 수 있는 오차(mismatch)를 근원적으로 제거한 것을 가장 큰 특징으로 들 수 있다. 또한 변환 과정을 16 비트 연산으로 가능하도록 설계한 것 또한 여타 표준과 구별 할 수 있는 특징이라 하겠다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.234-238
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• 2006

In this research, an analysis of damaged instance and forming fault for disc part in automotive steel wheel was performed. Rolled steel material, which had been used in the manufacturing of the damaged disc part, was prepared for tensile test, quantitative analysis of chemical component and acquirement of scanning electron microscope images. Although the results of mechanical properties and chemical component ratio for the material satisfied the suggested specification, some material inherent problem was found in the scanning electron microscope images. Finally, in an analysis of chemical component for the damaged disc part used in road condition, mismatching of chemical component ratio between the suggested specification and test result was found.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1660-1668
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• 2008

The WiBro was adopted to the 3G international standard. By the change of specification from Wave 1 to Wave 2, MIMO technology is applied in order to increase the speed of downlink. By MIMO the RF part of WiBro base station is increased to 2 Tx paths. Therefore, the size of RF part is bigger and material cost is increased. For reducing these demerits, the RF part which is consisted of PA, LNA, and TDD switch is designed to one complex RF unit. Also, the experimental results of the RF unit have been discussed. Since the complex RF unit is more compact than the RF part of Wave 1 base station, it can be used as the RF part of Wave 2 base station with 2T/2R MIMO.