• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.930-935
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• 2001

The experimental characterization of hydrodynamic bearing spindle motor is performed for the practical implementation of high-performance hard disk drive system. Firstly, the design concept of hydrodynamic bearing for the disk drive system is addressed including the herringbone grooved journal bearing, the spiral grooved thrust bearing, capillary seal design, and the viscous pumping of fluid. Secondly, the experimental evaluation is performed for the disk drive system in which the hydrodynamic bearing spindle motor is implemented and its dynamic performances are compared with conventional ball-bearing spindle motor. The key parameters include NRRO(Non Repeatable Run-Out), disk dynamics, acoustics, and resultant PES (Position Error Signal). Finally, the external gyro-exciting test results including 200k CSS(Continuous Start-Stop) on three angular attitudes(0,90, 180 degree) are presented in order to verify the practical reliability of disk drive system subject to the gyro-motion of hydrodynamic bearing spindle motor.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.127-139
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• 2006

Mt. Yokmang landscape design awarded first in [North container terminal site furtherance construction in Busan new port], design competition sponsoring in the Korea Container Terminal Authority in 2005. Design guideline was to propose the symbol of new port and to establish landscape plan in consideration of view and geological location. Because landscape plan required establishment of restoration plan for cutting slope, Mt. Yokmang became the major object. The purpose of planning are as follows. The first purpose is to minimize existent natural environment damage, and the second, to connect with ambit and create new image. The third is to provide place of rest and interchange for local resident. Reflecting stratum structure and landscape characteristics, cutting slope consisted of [utilization slope], [presentation slope], [landscape slope], and [ecological slope]. Vegetation design applied ecological restoration method through restoration of stratum, and eve environment-friendly afforestation, planned program that can connect area with existing ecosystem. In process that decides form of the cutting slope, analyze view structure and visual exposure in various access routes, sensitivity etc. was accomplished. Also, symbolic tower(Ocean Polaris) that presents in architecture and landscaping features, night landscape planning could gain synergy effect by keeping consistence with landscape and ecological planning. Passing through final design and construction process, I expect that the Mt. Yokmang will be a new landmark in Busan new port.

• Journal of the Korean Society of Costume
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• v.5
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• pp.141-152
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• 1981

Various ceremonial flags were of great importance to the rulers who wished to have the absolute authorities for governing the people. Perhaps nothing indicated the ideas, thoughts and symbols of a certain period and people than the ceremonial flags. The ceremonial flags used in the old China and Korea took the shapes of the heaven and the earth, representing the social backgrounds and thoughts. This study was limited only to the discussion of the heaven-shaped patterns of the ceremonial flags. The 28 constellations of the heaven, in the Oriental way of thinking, were considered to express the immortal powers of Providence and the political domination of the earth. Hence the Polaris, the center of the heaven, symbolized the whole family of king, prince, child born of a concubine and royal harem. Among the constellation pictures were those of Han period, wall painting of old tombs in Koguryeo kingdom and old Japanese kingdom. Referring to the Emperor's ceremonial flags in Daemyeongjibyei, symbolic meanings changed historically and the complete systems of the ceremonial flags were established in Song period when the divine person was drawn on the flags. Animals concerned properly with the particular star and the shapes of the star were both drawn on the flags in Won period and only the shapes of the particular star in Myeong period. In the Imperial enthronement of Kojong the ceremonial flags might be made by the examples of those of Myeong period and remains are now found at Changdeok Palace, which need a further study because the references in detail are not available.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.2
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• pp.51-58
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• 2023

This paper proposes a deep learning method for estimating the heart rate from facial videos. Our proposed method estimates remote photoplethysmography (rPPG) signals to predict the heart rate. Although there have been proposed several methods for estimating rPPG signals, most previous methods can not be utilized in low-power single board computers due to their computational complexity. To address this problem, we construct a lightweight student model and employ a knowledge distillation technique to reduce the performance degradation of a deeper network model. The teacher model consists of 795k parameters, whereas the student model only contains 24k parameters, and therefore, the inference time was reduced with the factor of 10. By distilling the knowledge of the intermediate feature maps of the teacher model, we improved the accuracy of the student model for estimating the heart rate. Experiments were conducted on the UBFC-rPPG dataset to demonstrate the effectiveness of the proposed method. Moreover, we collected our own dataset to verify the accuracy and processing time of the proposed method on a real-world dataset. Experimental results on a NVIDIA Jetson Nano board demonstrate that our proposed method can infer the heart rate in real time with the mean absolute error of 2.5183 bpm.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.346-354
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• 2020

Pectobacterium, which causes soft rot disease, is divided into 18 species based on the current classification. A total of 225 Pectobacterium strains were isolated from 10 main cultivation regions of potato (Solanum tuberosum), napa cabbage (Brassica rapa subsp. pekinensis), and radish (Raphanus sativus) in South Korea; 202 isolates (90%) were from potato, 18 from napa cabbage, and five from radish. Strains were identified using the Biolog test and phylogenetic analysis. The pathogenicity and swimming motility were tested at four different temperatures. Pectolytic activity and plant cell-wall degrading enzyme (PCWDE) activity were evaluated for six species (P. carotovorum subsp. carotovorum, Pcc; P. odoriferum, Pod; P. brasiliense, Pbr; P. versatile, Pve; P. polaris, Ppo; P. parmentieri, Ppa). Pod, Pcc, Pbr, and Pve were the most prevalent species. Although P. atrosepticum is a widespread pathogen in other countries, it was not found here. This is the first report of Ppo, Ppa, and Pve in South Korea. Pectobacterium species showed stronger activity at 28℃ and 32℃ than at 24℃, and showed weak activity at 37℃. Pectolytic activity decreased with increasing temperature. Activity of pectate lyase was not significantly affected by temperature. Activity of protease, cellulase, and polygalacturonase decreased with increasing temperature. The inability of isolated Pectobacterium to soften host tissues at 37℃ may be a consequence of decreased motility and PCWDE activity. These data suggest that future increases in temperature as a result of climate change may affect the population dynamics of Pectobacterium.

• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.61-70
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• 2012

In this study, a simple post-reconstruction dual-energy computed tomography (CT) method is proposed. A dual-energy CT algorithm for monochromatic x-rays was adopted and applied to the dual-energy CT of polychromatic x-rays by assigning a representative mono-energy. The accuracy of algorithm implementation was tested with mathematical phantoms. To test the sensitivity of this algorithm to the inaccuracy of representative energy value in energy values, a simulation study was performed with mathematical phantom. To represent a polychromatic x-ray energy spectrum with a single-energy, mean energy and equivalent energy were used, and the results were compared. The feasibility of the proposed method was experimentally tested with two different micro-CTs and a test phantom made of polymethyl methacrylate (PMMA), water, and graphite. The dual-energy calculations were carried out with CT images of all possible energy pairs among 40, 50, 60, 70, and 80 kVp. The effective atomic number and the electron density values obtained from the proposed method were compared with theoretical values. The results showed that, except the errors in the effective atomic number of graphite, most of the errors were less than 10 % for both CT scanners, and for the combination of 60 kVp and 70 kVp, errors less than 6.0 % could be achieved with a Polaris 90 CT. The proposed method shows simplicity of calibration, demonstrating its practicality and feasibility for use with a general polychromatic CT.

• Journal of Fashion Business
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• v.1 no.2
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• pp.1-19
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• 1997

This thesis is a reflection of Korean aestheticism and how it has evolved and influenced Korean contemporary fashion throughout the last century. Up to the current, there have been five notable trends of fashion that have been influenced from and have reflected the qualities emblematic of various periods in Korean history. They can be characterized as the era of Missionary fashion, Uniform fashion, Salon fashion, Brand Name Fashion, and finally, fashion from the current era of diversification. The specific characteristics of each fashion era have been analized and illustrated in a comprehensive table. Design characteristics of Korean contemporary fashion are as follows : 1. A point of emphasis is given to facial feature, unconstructive design and ample silhouette and A silhouette, two-piece and pants. Korean style wrap skirt, a smooth curve and layered style. 2. Effect of flatness from material; as methods of quilting, reinforced dual stitching(Kaeki), patchwork, embroidery and goldfoil thread extra, it is turned up that texture of cloth stuff and effects of flatness. 3. Simple color combinations give effects in two different directions For instance, white and a variety of vivid colors, a dull color and bright colors, black, blue. 4. Over-design, diffusion of fashion. Based on the design characteristics described above, the essence of Korea's beauty consciousness can be captured and summarized through the following points: 1. Emotionalism and non-characterism: traditional and simple natural beauty and modernized natural beauty. 2. From authoritism to non-authoritism: traditional and formal personal beauty and casual characteristic beauty. 3. Polaris (antithesis) phenomenon: chastic beauty and ostentatious beauty, simplicity and lavishness, conformity of fashion and originality. Although the beauty consciousness of Korean contemporary fashion is changing from traditional passive metaphor to aesthetic expressionism for the new generation, after all the basic foundation or root of the spiritual beauty of idealism is usually recognized by focusing on the face.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.3
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• pp.371-384
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• 2011

This study with 'trip' as a theme, aims to develop textile designs and fashion bags for travel which is widely applicable fitting traveler's T P O, applying Victor Vasarely's artwork. During the planning process of design, 'Whenever & Wherever's concept was set by analyzing fashion trend information in 2010-11 F/W proposed by Interfashion Planning and FCK; in addition, 'Bobos' were selected as research targets. It organized 4 images of 'Modern', 'Romantic', 'Classic' and 'Fantastic'. The motives are proposed textile design with '$Cross^2$', 'Falling Z', 'Cir-Classicism' and 'Skinny-holic' per each theme. The designs developed were printed out and into polyester canvas with a Polaris V6 DTP from dgen, Corp. Textile designs developed were applied for 'two-way' formed fashion bags for traveling with high practicality. Fashion bags for traveling consisted of big bags, tote bags, and hip sacks; a total of 12 works (4 sets per theme) were produced. This study sought practical plans for artworks by producing fashion goods through a DTP system. The results of this study can be used as guidelines for further studies and as a significant contribution to the creation of high values for exciting fashion products.

• Cross-Cultural Studies
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• v.35
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• pp.185-214
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• 2014

This paper presents an investigation into the forms of master archer Huhdai Mergen from Mongolian mythology and his character through archery. In Mongolian mythology, master archer Huhdai Mergen is usually connected to the regulation of the sun, the moon, and the stars in Heaven and the creation of stars. Such a series of acts are conducted through archery, which used to be performed as an incantatory ritual to resolve a disaster in life, dispel an evil spirit, and pray for affluence as well as for hunting. In Mongolian mythology, Huhdai Mergen is a master archer and hunter that rises to Heaven while hunting a deer and becomes Sirius with the deer becoming Orion. The Mongolian have believed that the two constellations protect them since ancient times. While Orion is related to the deer totem, Huhdai Mergen or Sirius is related to the wolf totem faith. Huhdai Mergen takes too much pride in his archery skills and ends up causing damage to himself, which can be understood as a pattern of controlling the power of personified Huhdai Mergen through excessive natural force. He also has something to do with Polaris, which is regarded as the stake to bind his horse to by the Mongolian. They also believe that their ancestral gods reside in the horse stake or column. The stake is the residence of Huhdai Mergen protecting the Mongolian people, which reflects his aspect as an ancestral god. He is also depicted as the god of thunder and lightning born in a cow. The stones he throws and the arrows he shoots in Heaven are the embodiments of thunder and lightning. The Mongolian have understood lightning of dispelling an evil spirit and striking wicked things as the arrow of Huhdai Mergen. The god of thunder and lightning has the attributes of a fertility god such as eliminating bad devils and bringing affluence. Huhdai Mergen is also manifested as the creator to create the earth and the savior to save mankind. Such forms all derive from his archery skills.

• Journal of Ecology and Environment
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• v.47 no.1
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• pp.1-13
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• 2023

Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.