• Journal of Korea Multimedia Society
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• v.12 no.8
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• pp.1109-1119
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• 2009

WLAN(Wireless Local Area Network) standard is currently developing with increased wireless internet demand. Though existing IEEE 802.11e demonstrates that data rates exceed 54Mbps with assuring QoS(Quality of Service), wireless internet users can't be satisfied with real communication system. After IEEE 802.11e system, Study trends of IEEE 802.11n show two aspects, enhanced system throughput using aggregation among packets in MAC (Medium Access Control) layer, and better data rates adapting MIMO(Multiple-Input Multiple-Output) in PHY(Physical) layer. But, no one demonstrates IEEE 802.11n system performance results considering MAC and PHY connection. Therefore, this paper adapts MIMO in PHY layer for IEEE 802.11n system based on A-MPDU(Aggregation-MAC Protocol Data Unit) method in MAC layer considering MAC and PHY connection. SVD(Singular Value Decomposition) method with WLAN MIMO TGn Channel is used to analyze MIMO. Consequently, Simulation results show enhanced throughput and data rates compared to existing system. Also, We use Ns-2(Network Simulator-2) considering MAC and PHY connection for reality.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.381-381
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• 2019

동남아시아의 급격한 도시인구 증가는 도시화로 파생되는 제반문제를 유발하고 있으며 특히 집중호우와 홍수배제 시설의 부족 및 유관시설의 정보관리체계 부재는 홍수 피해규모를 가중시키고 있다. 인도네시아의 경우 물 재해 관리기관 간의 정보공유체계 부재로, 홍수로 인한 문제해결에 대하여 효과적인 대응이 어려운 실정이다. 주요 물 관리 기관인 유역관리청(BBWS)의 경우 조기홍수경보시스템을 보유하고 있으나 단순 수문현황 모니터링에 국한되어 운영되고 있다. 이에 본 연구에서는 홍수피해를 최소화 할 수 있는 동남아시아 맞춤형 물 재해 관리 클라우드 플랫폼을 개발하여 비구조적 홍수 문제해결의 매개체로 활용하고자 한다. 기본적인 유역 수문현황 모니터링과 함께 댐, 보, 배수문 및 펌프장 등 홍수방어시설물의 운영현황 정보, 홍수상황분석, 홍수위험지도 등 종합적인 물 재해 정보를 제공하고 사전에 홍수위험 지역을 분석하여 유관기관과 공유할 수 있는 물 재해 관리 의사결정지원시스템을 개발하고자 한다. 기본적인 정보관리 체계화를 위하여 인도네시아의 다양한 물 재해 관련기관에서 보유하고 있는 자료들의 통합 클라우드 DB관리 시스템을 구축하였다. 연구대상지역은 인도네시아 수도인 자카르타의 Pesanggrahan유역과 인근 Batam섬 Baloi유역을 선정하였으며 대상 유역의 수문, 기상자료 및 GIS 정보수집은 공동연구기관인 인도네시아 공공사업부 수자원청(MPWH)과 주요 물 관리기관인 유역관리청(BBWS)의 협조를 통하여 진행하였다. 수집된 자료들은 관계형 데이터베이스 관리시스템인 MySQL을 사용하여 통합 물 재해 정보 데이터베이스를 구축하였으며 완성된 데이터베이스의 정보제공 및 공유시스템은 웹기반 인터페이스를 통해 관리되도록 설계하였다. 홍수유출 해석을 위한 분석 엔진은 K-water의 홍수분석 시스템인 FAS를 이용하였다. FAS의 홍수분석모형인 COSFIM과 수리모형인 Fldwav를 연계하는 데이터 분석 플랫폼을 완성하였으며 인도네시아 현지 조건에 부합하는 홍수분석 시스템으로 Customizing과정을 수행하였다. 또한 FAS의 PC기반 시뮬레이션 형식을 DB 연계형 웹서비스 방식으로 연동되도록 개량하였으며 추후 SaaS형 물 재해 분석시스템으로 전환할 수 있는 개발환경을 확보하였다. 개발된 물 재해 분석 플랫폼(WRMP)을 활용하여 인도네시아 공동연구기관과의 협의를 통해 물 재해 관리 시나리오를 수립하고 그 대안을 제시하였으며, 적용 시나리오별 홍수피해 저감 효과를 분석하였다. 또한 향후 방재시설물까지 연계하여 운영효과를 분석할 수 있도록 구조화하였다. 개발된 물 재해 관리 시스템은 개선된 정보처리 및 분석시스템을 활용하여 종합적인 물 재해정보를 제공하고, 사전에 홍수위험 지역을 분석하여 유관기관과 공유할 수 있는 물 재해 관리 의사결정 지원시스템으로써 유용하게 활용될 수 있을 것이다.

• (The)Study of the Eastern Classic
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• no.62
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• pp.9-35
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• 2016

This study examined Songgye Na-sik's(松桂懶湜, 1684~1765) literary world based on Priest Songgye's Anthology(松桂大禪師文集). In consideration of the insufficiencies of the only previous study on Songgye's literature, this study was focused on his ideological character and its historicity, the trend of literary exchange in the Buddhist circle, and the literary geographical aspect of his literature. Priest Songgye was the head of the Bonghwa-sa Temple in Andong during the years under the rule of Kings Sukjong and Yeongjo, and learned from Hwanseong Ji-ahn(喚醒志安, 1664~1729) and Nakam Eui-nul(落巖義訥, 1666~1737). The priest did not have many students under him nor leave numerous writings. In the process of the development of the Buddhist doctrines in the late Joseon Dynasty, however, he completed the scripture learning courses faithfully and laid the ground of his philosophy. In addition, the afterword of Hwaeomgyeongchilcheogupumhoipummok (華嚴經七處九會品目跋) shows that he compiled the book under his teacher's instruction. What is more, he is known to have devoted himself to belief in the Pure Land in his late years. Given these backgrounds, the priest's life, writings, and ideological tendencies pursued all of Zen, Hwaeom, and the Pure Land together, and at the same time, reflected the characteristics of Korean Buddhism in the 18th century. The priest steadily cultivated himself in poetry and established his own literary world, and all the outcomes were fully reflected in his anthology. Priest Songgye walked the road of a learner throughout his lifetime but, on the other hand, he established his identity as a literary man in the specific time and space of Andong, Yeongnam in the late Joseon Dynasty.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.63-70
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• 2022

Although 2D Object detection has been largely improved in the past years with the advance of deep learning methods and the use of large labeled image datasets, 3D object detection from 2D imagery is a challenging problem in a variety of applications such as robotics, due to the lack of data and diversity of appearances and shapes of objects within a category. Google has just announced the launch of Objectron that has a novel data pipeline using mobile augmented reality session data. However, it also is corresponding to 2D-driven 3D object detection technique. This study explores more mature 2D object detection method, and applies its 2D projection to Objectron 3D lifting system. Most object detection methods use bounding boxes to encode and represent the object shape and location. In this work, we explore a stochastic representation of object regions using Gaussian distributions. We also present a similarity measure for the Gaussian distributions based on the Hellinger Distance, which can be viewed as a stochastic Intersection-over-Union. Our experimental results show that the proposed Gaussian representations are closer to annotated segmentation masks in available datasets. Thus, less accuracy problem that is one of several limitations of Objectron can be relaxed.

• The Journal of Bigdata
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• v.7 no.2
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• pp.173-193
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• 2022

With the revision of the Data 3 Act, the financial MyData industry was created newly. MyData services collect the financial customers' data scattered in various financial companies and provide personalized services such as personal financial product recommendation, personal expenditure advice, etc. Although MyData service started in 2022, but the use of the service has not been significantly activated. This study attempted to analyze the factors affecting the use of MyData services from the perspective of financial consumers through VAM, UTAUT2 model. The factors related to the perceived value and intention to use MyData services of financial consumers were verified using benefit and sacrifice variables. Personal Innovativeness was used as a moderating variable. As a result of this study, it was found that personal product recommendation service has an important influence on the use of MyData services, and personal innovativeness has an effect as a modulating variable. It can be said that it is meaningful as a preceding study in terms of timing because it studied the perceived value of consumers less than a year after the MyData service began. From the practical perspectives, it was possible to show the change direction and marketing points of the MyData service. In practice, it was possible to confirm the direction of the service and the marketing point.

• Journal of KIISE:Software and Applications
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• v.31 no.10
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• pp.1332-1344
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• 2004

Upon development of information super-highway and multimedia-related technoiogies in recent years, more efficient technologies to transmit, store and retrieve the multimedia data are required. Among such technologies, firstly, it is common that the semantic-based image retrieval is annotated separately in order to give certain meanings to the image data and the low-level property information that include information about color, texture, and shape Despite the fact that the semantic-based information retrieval has been made by utilizing such vocabulary dictionary as the key words that given, however it brings about a problem that has not yet freed from the limit of the existing keyword-based text information retrieval. The second problem is that it reveals a decreased retrieval performance in the content-based image retrieval system, and is difficult to separate the object from the image that has complex background, and also is difficult to extract an area due to excessive division of those regions. Further, it is difficult to separate the objects from the image that possesses multiple objects in complex scene. To solve the problems, in this paper, I established a content-based retrieval system that can be processed in 5 different steps. The most critical process of those 5 steps is that among RGB images, the one that has the largest and the smallest background are to be extracted. Particularly. I propose the method that extracts the subject as well as the background by using an Image, which has the largest background. Also, to solve the second problem, I propose the method in which multiple objects are separated using RGB channel selection techniques having optimized the excessive division of area by utilizing Watermerge's threshold value with the object separation using the method of RGB channels separation. The tests proved that the methods proposed by me were superior to the existing methods in terms of retrieval performances insomuch as to replace those methods that developed for the purpose of retrieving those complex objects that used to be difficult to retrieve up until now.

• The Journal of Korean Philosophical History
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• no.43
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• pp.9-32
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• 2014

Until now, the studies researching the Taoism theories of Joseon Dynasty have mainly dealt around the latter half of Joseon Dynasty. The reason for that was because the 5 cribs of a book Lao Tzu and the 2 crib of a book Changzi were produced after the Imjin-Year Korean-Japanese War(壬辰倭亂,Imjin Waeran). Therefore this thesis extracted the mentions about Taoism from about 200-year history records from Jeong Do-Jeon's Theory, which was the theoretical foundation for early days of Joseon's foundation and the history book King Taejong's Annals(太宗實錄) contained in The Annals of Joseon Dynasty(朝鮮王朝實 錄) and analyzed the extracted historic data as the first work contemplating how the Taoism theories were developed during the first half of Joseon Dynasty. From the analysis, this study drew out the findings as follows. Jeong Do-Jeon and Gwon Geun sharply criticized the Taoism for that it pursued for the techniques of longevity for oneself without moral. They tried to establish the identity of neo-Confucianism on the foundation criticizing the Taoism and the Buddhism. Since then, the Taoism was transformed through the 3 stages in The Annals of Joseon Dynasty. The first stage was the stage transformed 'Lao Tzu' as the witchcraft master of long-live, the technique of the taoist hermit and the super god in Taoism, and regarded the Taoism as heresy and excluded the Taoism. Second stage was the stage trying to see the book Lao Tzu as the core of Taoism theory separately from the 'Hermit Witchcraft' and the 'Taoist gods' the target of fortune-pursue religion beyond from the primary discussion of exclusion. Third stage was revealed as the respects on the art of politics and the art of living described in the book Lao Tzu. That is, the Taoism theories in the first half of Joseon Dynasty was developed with various spectrums from the early days of Joseon's foundation to 15~16 centuries beyond Joseon's strong suppression against the Taoism and the Buddhism in early days. That is the point that the Taoism in the first half of Joseon Dynasty can't be simply interpreted in the neo-Confucianism. During the firs half of Joseon Dynasty, the warm attitude toward the Taoism was created differently from the attitude against suppressing it as a cult, which had been created in the early days of Josen's foundation, and there appeared the changes accepting the art of living and the art of politics theoretically integrating with the Confucianism theories. That is, the book 'Lao Tus' became accepted as the Confucian country's arts of living and politics from a cult book pursuing for immoral log and immortal life. Such acception is revealed as the appearance actively interpreting the books about Laoism in the latter half o Joseon Dynasty.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.679-684
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• 2005

There are a few representative wireless network access technologies used widely. WWAN is celluar based telecommunication networks supporting high mobility, WLAN ensures high data rate within hotspot coverage, and WDMB support both data and broadcasting services correspondingly. However, these technologies include some limitations especially on the mobility, data rate, transmission direction, and so on. In order to overvome these limitations, there are various studies have been proposed in terms of 'Vortical Handoff' that offers seamless connectivity by switching active connection to the appropriate interface which installed in the mobile devices. In this paper, we propose the interface selection algorithm and network architecture to maximize the life time of entire system by minimizing the unnecessary energy consumption of another interfaces such as WLAN, WDMB that are taken in the user equipment. In addition, by using the results of analyzing multiple types of traffic and managing user buffer as a metric for vertical handoff, we show that the energy efficiency of our scheme is $75\%$ and $34\%$ than typical WLAN for WDMB and WLAN preferred schemes, correspondingly.

• Journal of Information Technology and Architecture
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• v.11 no.4
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• pp.409-426
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• 2014

Korea has won 3 times in a row in the evaluation of e-government services in 2014. And the last year, the government-EA has been awarded the UN Public Service Award. Because of the development and execution of personalized integrated services based on the government-EA, Korea has won the two award from the UN. EA has been selected and proceeded as one of the 31 e-Government projects in early period, in 2005 the law which public sector must adopt the EA for efficient informatization had been enacted. Many public agencies in which actively utilized to derive such as internal and external performance through the EA. On the other hand, in the last 10 years, some public agencies have still been as recognized level of management in the EA. In this study, the main purpose is that to find out what is a major factor for successful use and result of EA, what is the EA success Model and how to examine it. To do that, this study will study the related prior research such as EA services, information systems success factors, performance measures, and develop the success model for EA and then examine the model. This study will contribute great implications in practical and theoretical in EA success model because this is the nation's first research that SERVQUAL model and the IS Success Model(DeLone & McLean 2003) has been combined and examined.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.681-682
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• 2013

전기는 우리 주변의 에너지 형태 중에서 가장 편리하고 광범위하게 사용되고 있다. 이러한 전기는 전자제품, 전기자동차, 에너지 저장 플랜트 등 매우 많은 분야에서 저장되고 사용되고 있다. 특히 에너지 저장 용량의 확대는 휴대폰, 노트북 PC 등 휴대용 IT 기기의 성장에 결정적인 역할을 하였다. 가볍고 작으면서도 고용량의 전기 에너지 저장 장치가 없었다면, 통신이나 인터넷 그리고 오락 등 다양한 기능을 작은 휴대용 기기에 구현할 수 없었을 것이다. 그러나 시간이 흐를수록 기기의 요구 성능이 높아지고 소비자의 니즈가 더욱더 다양해지고 고도화될수록 단일 부품으로 가장 큰 부피를 차지하는 에너지 저장 장치의 용량과 디자인은 점점 중요해지고 있다. 이러한 에너지 저장 장치에서 가장 친숙한 형태는 2차 전지 계열이다. 납 축전지를 비롯하여, 니켈수소, 니켈카드뮴, electrochemical capacitor와 Li ion 계열 등이 대표적이다. 특히 Li ion 배터리는 모바일, 자동차 및 에너지 저장 그리드 등과 같은 다양한 분야에 가장 많이 적용되고있다. Li ion 배터리에 대하여 현재의 핵심적인 연구분야는 전극 재료(cathode, anode)와 electrolyte에 대한 것이다. Anode 전극 재료 중에서 가장 많이 사용되는 재료는 카본을 기반으로 하는 재료로 안정성에 대한 장점이 있지만 에너지 밀도가 낮다는 단점이 있다. 에너지 저장 용량 증가에 대한 필요성이 증가하기 때문에 현재 많이 사용되고 있는 에너지 밀도가 낮은 카본 재료를 대체하기 위해서 이론 용량이 높다고 알려진 실리콘과 같은 메탈이나 주석 산화물과 같은 천이 금속 산화물에 대하여 많은 연구가 진행되고 있다. 특히 현재까지 알려진 많은 재료 중에서 가장 큰 capacity (~4,000 mAh/g)를 가지고 있다고 알려진 실리콘이 카본의 대체 재료로 많은 연구가 진행되고 있다. 그러나, Li 과 반응을 하며 약 300~400%에 달하는 부피팽창이 발생하고, 이러한 부피 팽창 때문에 충 방전이 진행됨에 따라 current collector로부터 박리되는 현상을 보여 빠른 용량 감소를 보여주고 있다. 본 연구에서는 adhesion layer를 current collector와 실리콘 전극 재료 사이에 삽입하여 충 방전 시 부피팽창에 의한 미세구조의 변화와 electrochemical 특성에 대한 영향을 알아보았다. 실험에 사용한 anode 전극은 상용 Cu foil current collector에 RF/DC magnetron 스퍼터링을 통해 다양한 종류(Ti, Ta 등)의 adhesion layer과 200 nm 두께의 Si 박막을 증착하였다. 또한 Bio-logic Potentiostat/ Galvanostat VMP3 와 WanAtech automatic battery cycler 장비를 사용하여 0.2 C-rate로 half-cell 타입의 코인 셀로 조립한 전극에 대한 충 방전 실험을 진행하였다. Adhesion layer의 사용으로 인해 실리콘 박막과 Cu current collector 사이의 박리 현상을 줄여줄 수 있었고, 충 방전 시 Cu 원자의 실리콘 박막으로의 확산을 통한 brittle한 Cu-Si alloy 형성을 막아 줄 수 있어 큰 특성 향상을 확인할 수 있었다. 또한, 리튬과 실리콘의 반응을 통한 형태와 미세구조 변화를 SEM, TEM 등의 다양한 장비를 사용하여 확인하였고, 이를 통해 adhesion layer의 사용이 전극의 특성향상에 큰 영향을 끼쳤다는 것을 확인할 수 있었다.