• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.10a
• /
• pp.167-170
• /
• 2003

In this paper, the electromechanical displacements of curved actuators using laminated composites are calculated by finite element method to design the optimal configuration of curved actuators. To predict the pre-stress in the device due to the mismatch in coefficients of thermal expansion, the carbon-epoxy and glass- epoxy as well as PZT ceramic is also numerically modeled by using hexahedral solid elements. Because the modeling of these thin layers causes the numbers of degree of freedom to increase, large-scale structural analyses are performed in a cluster system in this study. The curved shape and pre-stress in the actuator are obtained by the cured curvature analysis. The displacement under the piezoelectric force by an applied voltage is also calculated to compare the performance of curved actuator. The thickness of composite is chosen as design factor.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.04a
• /
• pp.87-90
• /
• 2003

In this paper, the electromechanical displacements of curved actuators such as THUNDER are calculated by finite element method to design the optimal configuration of curved actuators. To predict the pre-stress in the device due to the mismatch in coefficients of thermal expansion, the adhesive as well as metal and PZT ceramic is also numerically modeled by using hexahedral solid elements. Because the modeling of these thin layers causes the numbers of degree of freedom to increase, large-scale structural analyses are performed in a cluster system in this study. The curved shape and pre-stress in the actuator are obtained by the cured curvature analysis. The displacement under the piezoelectric force by an applied voltage is also calculated to compare the performance of curved actuator. The thickness of metal and adhesive, the number of metal layer are chosen as design factors.

• Korean Institute of Interior Design Journal
• /
• v.21 no.5
• /
• pp.77-84
• /
• 2012

Single formative language created by the standardization of industrial society carries a cell constructive aspect. Such space structural form made gigantic buildings, which has a symbolism as an independent object. Such space shows a morphological symbolism by public preference but it did not establish essential meaning of a shape or concentrated relation. In this regard, this paper tries to show organic similarity of structural formality of small commercial space (patterned space), which was made by the continuity of concentrated patterns not an object of dualistic unit features. Therefore, this study analyzed the cultural, commercial and public space based upon systematical concept and features. Systematical space formality that makes multilateral relation between human, environment and a thing is a concentrated view point by relational features not by the cluster displayed by hierarchical features. Systematical space of small patterned space emphasized its appropriateness of expansion and creating diversified spaces unlike gigantic symbolic buildings.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.48.1-48.1
• /
• 2019

Mass and radius of a neutron star in low-mass X-ray binary (LMXB) can be estimated simultaneously when the observed light curve and spectrum show the photospheric radius expansion feature. This method has been applied to 4U 1746-37 and the mass and radius were found to be unusually small in comparison with typical neutron stars. We re-estimate the mass and radius of this target by considering that the observed light curve and spectrum can be affected by other X-ray sources because this LMXB belongs to a very crowded globular cluster NGC 6441. The new estimation increases the mass and radius but they do not reach the typical values yet.

• Journal of the Economic Geographical Society of Korea
• /
• v.21 no.4
• /
• pp.303-320
• /
• 2018

This study analyzes the characteristics of the evolution process of the Gumi National Industrial Complex as well as its external and internal drivers based on the cluster adaptation cycle model. The Gumi National Industrial Complex has made remarkable progress through expansion in spatial and industrial realm and has become a representative IT industry cluster in Korea. It evolved during a growth period from the 1990s, a maturity period from the mid-2000s, and a mature stagnation period from the mid-2010s. But it has now entered a period of decline. While external drivers at the international and national level greatly influenced the Gumi National Industrial Complex in its evolution from foundation-building to maturity, internal drivers such as the outflow of large firms as well as a lack of SME research capacity and institutional base have added to the management difficulties of SMEs in the mature stagnation period. Therefore, in order for the Gumi National Industrial Complex to move into a revitalization period that strengthens resilience against external shocks, it is necessary to enhance the capacity of SMEs by expanding the roles of the central government, local government, and support agencies. In addition, it is necessary to create and embed strong medium enterprises within the Gumi National Industrial Complex, so that the Complex can be reborn as a sustainable innovation ecosystem.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.12
• /
• pp.3874-3884
• /
• 2000

An information retrieval system has to retrieve all and only documents which are relevant to a user query, even if index terms and query terms are not matched exactly. However, term mismatches between index terms and qucry terms have been a serious obstacle to the enhancement of retrieval performance. In this paper, we discuss automatic term normalization between words in text corpora and their application to a Korean information retrieval system. We perform two types of term normalizations to alleviate semantic term mismatches: equivalence class and co-occurrence cluster. First, transliterations, spelling errors, and synonyms are normalized into equivalence classes bv using contextual similarity. Second, context-based terms are normalized by using a combination of mutual information and word context to establish word similarities. Next, unsupervised clustering is done by using K-means algorithm and co-occurrence clusters are identified. In this paper, these normalized term products are used in the query expansion to alleviate semantic tem1 mismatches. In other words, we utilize two kinds of tcrm normalizations, equivalence class and co-occurrence cluster, to expand user's queries with new tcrms, in an attempt to make user's queries more comprehensive (adding transliterations) or more specific (adding spc'Cializationsl. For query expansion, we employ two complementary methods: term suggestion and term relevance feedback. The experimental results show that our proposed system can alleviatl' semantic term mismatches and can also provide the appropriate similarity measurements. As a result, we know that our system can improve the rctrieval efficiency of the information retrieval system.

• Journal of Distribution Science
• /
• v.12 no.6
• /
• pp.59-65
• /
• 2014

Purpose - The competitiveness of logistics in the 21st century rests on ensuring the efficiency and effectiveness of its local hub. While considering entry into a niche market in local logistics, it is pertinent to note that Budapest is emerging as a hub in EU enlargement in Eastern Europe. Big, small, and medium-sized businesses in Korea entered Hungary in the early 1990s since then, there has been a significant increase in Korean presence, of approximately 130 times. This study aimed to identify the key distribution issues that have emerged in relation to Eastern Europe. Research design, data, and methodology - This study indicates that 33 major Korean companies were located in Hungary, which serves as an out post to enter the European marketplace. However, Korea's exports to Hungary have declined (-32.0% in 2012) because of a loss of competitiveness against multinational corporations, due to factors such as the rise in current local distribution costs and wages. Hungary, on the other hand, through diversification and expansion of foreign trade with the non-EU markets, including Korea, is increasing its exports. Strategies of emerging countries are compared and reviewed in this study, by examining the vicissitudes of Hungary's distribution methods. Results - There are issues regarding Hungary's innovative ability. Hungary has a history of low wages and high skilled labor. However, the outflow of high-quality human resources for high-wages has become more extensive, and this underlines concerns that the CEE's trade hub is moving to neighboring countries. After the European financial crisis in 2010, the Hungarian economy is now developing, because of the IMF's measures, and it is being transformed into a trade surplus nation, while regaining distribution volumes rapidly. However, if there is continued lack of investment, the supply chain is weakened and exports decline amidst competition with TNCs or with China's distribution networks. Conclusions - It is necessary to create a new logistics approach for increasing trade between Korea and Hungary. First, Korean small and medium enterprises (SMEs) should build trust by working with advanced Hungarian talent, and they should expand into state-of-the-art fields instead of being confined to traditional sectors. Second, this study focuses on limiting and lowering their high expectations for success according to foreign direct investment (FDI) inflows and the role in the CEE distribution hub Korea should try to strengthen the distribution hub with its centralized population, using better, more highly educated human resources, thereby sustaining more innovative ability. Further, the positive effects of these measures are manifested in enhanced business on both sides of Hungary, namely, the EU and non-EU nations such as Turkey and emerging markets around Europe, and a better engagement in the core placement of culture and industry. For this, Korea can contribute to, and benefit from, a Hungarian logistics center, for adopting the high-tech cluster systems and commercializing distribution technology such as RFID·USN.

• Korean Journal of Plant Taxonomy
• /
• v.40 no.3
• /
• pp.145-152
• /
• 2010

The external morphological characters of the Korean Oldenlandia were reviewed, and numerical analysis of 25 quantitative characters carried out to evaluate the delimitation of the taxa. Among the qualitative characters, the leaf shape, inflorescence, pilose of insde corolla, expansion of capsule apex, and seed shape were used to delimit 5 species of Korean Oldenlandia. As the result of principal component analysis of quantitative characters, O. corymbosa, O. hirsuta and O. strigulosa were evidently separated on a two-dimensional plot by PC1 and PC2, and O. brachypoda and O. diffusa slightly overlapped. However, O. brachypoda was distinctly delimited from O. diffusa by the shape of calyx lobe, the lengths of pedicel, filament and stigma. Also each of those two species was in a group of its own by cluster analysis.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.5
• /
• pp.103-113
• /
• 2009

In this study, we separated the precipitation zones using the geographic location of stations and precipitation characteristics (monthly, seasonal, annual) in Gangwon province. Precipitation data of 66 weather stations (meterological office: 11 locations, auto weather system (AWS): 55 places) were used, and statistical method, K-means cluster method, was conducted for division of the precipitation regions. As the results of regional classification, the five zones of precipitation (Yongdong: 1 region, Youngseo: 4 regions) were separated. Seasonal average precipitation in spring is similar throughout Gangwon Province, seasonal average precipitation in summer has high values at Youngseo, and seasonal average precipitation in autumn and winter have high values at Youngdong. The some areas, the vicinity of Misiryeong and Daegwallyeong, happens the orographic precipitation in spatial analysis, but the orographic effects didn't occur for the whole Gangwon areas. However, to achieve more accurate results, the expansion of observatories per elevation and AWS data are demanded.

• Journal of Information Technology Services
• /
• v.23 no.3
• /
• pp.103-118
• /
• 2024

Due to the advancement of virtual reality technology, virtual idols are widely used in industrial and cultural content industries. However, it is difficult to utilize virtual idols' social perceptions because they are not properly understood. Therefore, this paper collected and analyzed YouTube comments to identify differences about social perception through comparative analysis between virtual idols and general idols. The dataset was constructed by crawling comments from music videos with more than 10 million views of virtual idols and more than 10,000 comments. Keyword frequency and TF-IDF values were derived from the collected dataset, and the connection centrality CONCOR cluster was analyzed with a semantic network using the UCINET program. As a result of the analysis, it was found that virtual idols frequently used keywords such as "person," "quality," "character," "reality," "animation," while reactions and perceptions were derived from general idols. Based on the results of this analysis, it was found that while general idols are mainly evaluated with their appearance and cultural factors, social perceptions of virtual idols' values are mixed with evaluations of cultural factors such as "song," "voice," and "choreography," focusing on technical factors such as "people," "quality," "character," and "animation." However, keywords such as "song," "voice," "choreography," and "music" are included in the top 30 like regular idols and appear in the same cluster, suggesting that virtual idols are gradually shifting away from minority tastes to mainstream culture. This study aims to provide academic and practical implications for the future expansion of the industry and cultural content industry of virtual idols by grasping the social perception of virtual idols.