• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.135-140
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• 2002

The position and trajectory of in-flight rocket are important informations to determine the flight safety of rocket. In general tracking system, radar and transponder are used to acquire position information. Rocket position and trajectory can be determined by using RF communication between ground station and in-flight rocket and antenna position data. Onboard transponder system is composed of RF receiving part, RF transmitting one, decoder and single TX/ RX antenna. Therefore circulator is necessary for minimizing RF signal interference. In this paper, the radar transponder system was developed to track the trajectory and position of KSR-Ⅲ by using radar.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.2
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• pp.183-196
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• 2016

The academic journal is an important medium carrying newly discovered knowledge in various disciplines. It is desirable to consider visualization of journal and article information in order to make the information more insightful and effective than text-based information. In this study, visualization service platform of journal and article information is developed. TagCloud were included in both Infographics of journal and article. Each word in the TagCloud is inter-linked with DBPedia using Linked Open Data (LOD) technique.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.33-33
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• 2016

산사태 발생 예측은 재해를 예방하고 대처하기 위한 가장 근본적이며 효과적인 방법이나, 과학기술의 발전과 많은 노력에도 불구하고 아직 산사태의 발생 장소와 시기를 예측하는 것은 매우 어려운 일이다. 산사태 발생 예측 기법은 크게 경험론적 지수기법, 통계적 해석기법, 물리적 해석 기법으로 나뉠 수 있다. 이 세 방법은 각기 장단점이 있으나 일반적으로 후자로 갈수록 많은 데이터가 요구되고, 해석에 시간이 필요하며, 보다 신뢰할만한 결과를 도출할 수 있다. 경험론적 지수 기법은 국내에서 실무적으로 널리 활용되고 있으며, 통계적 해석기법에 관한 연구도 수행된 바 있다. 하지만 이 두 방법론은 일정량 또는 일정강도 이상의 강우 발생 시 산사태의 발생 위험도를 공간적으로 예측할 수 있으나, 산사태의 발생 시점과 연속적인 강우량 또는 강우강도의 관계를 정량적으로 분석하기 힘든 한계가 있어 최근에는 이러한 한계를 극복하기 위해 최근 무한사면안정 모형과 토양수분침투 모형을 결합한 시변 사면안정모형들이 활용되기 시작하고 있다. 대표적으로는 TRIGRS가 있으며, 이 모형에서는 선형화한 1차원 Richards 방정식의 해석해를 활용하여 토양수분량을 계산한 후 이 정보를 무한사면안정모형에 반영하여 시변적인 사면안정도를 구하고 있다. 하지만 Richards 방정식을 선형화하기 위해서 제한된 토양수분-압력 관계식이 사용되며, GUI가 제공되지 않아 전처리 및 후처리가 번거로운 한계가 있다. 본 연구에서는 이러한 한계를 개선하기 위해 3차원 Richards방정식을 수치적으로 계산하여 보다 다양한 토양수분-압력 모형과 초기조건을 반영할 수 있게 하였다. 또한 GUI를 지원하여 사용자가 보다 손쉽게 해석모형을 사용할 수 있도록 하였다.

• The Journal of the Acoustical Society of Korea
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• v.38 no.1
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• pp.120-127
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• 2019

Passive source depth discrimination has been studied for decades since the source depth can be used for discriminating whether the target is near the surface or submerged. In this thesis, an algorithm for source depth discrimination is proposed based on CIR (Channel Impulse Response) from target-radiated noise (or signal). In order to extract CIR without a known source signal, Ray-based blind deconvolution is used. Subsequently, intersections of CIR pattern, which is characterized by ray arrival time difference, is utilized for discriminating source depth. The proposed algorithm is demonstrated through numerical simulation in ocean waveguide, and verified via the experimental data.

• Journal of Soil and Groundwater Environment
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• v.28 no.spc
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• pp.18-39
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• 2023

Rapid development of geophysical exploration and hydrogeologic monitoring techniques has yielded remarkable increase of datasets related to groundwater systems. Increased number of datasets contribute to understanding of general aquifer characteristics such as groundwater yield and flow, but understanding of complex heterogenous aquifers system is still a challenging task. Recently, applications of data science technique have become popular in the fields of geophysical explorations and monitoring, and such attempts are also extended in the groundwater field. This work reviewed current status and advancement in utilization of data science in groundwater field. The application of data science techniques facilitates effective and realistic analyses of aquifer system, and allows accurate prediction of aquifer system change in response to extreme climate events. Due to such benefits, data science techniques have become an effective tool to establish more sustainable groundwater management systems. It is expected that the techniques will further strengthen the theoretical framework in groundwater management to cope with upcoming challenges and limitations.

• Annual Conference of KIPS
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• 2007.11a
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• pp.161-164
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• 2007

최근 인터넷과 멀티미디어 기술이 발달함에 따라 이미지 데이터의 양이 급속히 증가하고 있다. 증가하는 이미지를 효과적으로 관리하고 검색하기 위해 내용기반 이미지 검색에 대한 연구가 활발히 진행되고 있다. 대부분의 내용 기반 이미지 검색 시스템은 색상, 모양, 질감 특징을 이용한 유사도-기반검색에 초점을 맞추고 있다. 따라서 본 논문에서는 이미지에 나타나는 주요 색상과 색상의 공간적 특성을 포함하는 픽셀샘플링, 그리고 이미지의 외형적 변경에 강인함을 갖는 불변 모멘트 값을 이용한 내용기반 이미지 검색 시스템을 제안한다. 첫 번째 유사성 검사 단계에서는 이미지의 영역별로 가중치를 부여하여 추출한 대표색상을 사용하여, 유사하지 않은 이미지를 제거하여 검색대상의 수를 줄이며, 두 번째 유사성 검사 단계에서는 첫 번째 단계에서 선별된 후보 이미지에 색상의 공간적 정보를 포함한 픽셀샘플링을 이용하여 색상의 공간적인 위치까지 유사한 이미지만을 선별한다. 두 번째 유사성 검사단계에서 이미지가 외형적으로 변형된 유사이미지의 검출이 어려운 점을 보완하는 방법으로 이미지의 불변 모멘트를 이용하여 검색의 정확성을 높인다. 제안한 이미지 검색 방법은 10000개의 다양한 이미지로 구성된 데이터베이스에서 검색을 효율성을 실험하였다.

• Journal of Technology Innovation
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• v.14 no.1
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• pp.31-66
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• 2006

The country with a relative abundance of human capital conducts relatively more R&D in the steady state than its partner. This country acquires the know-how to produce a relatively wider range of innovative goods. High technology comprises a large share of the national economy in the human-capital rich country and real output growth is faster. This prediction would seem to accord weakly with empirical observation of Korean economy.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.799-806
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• 2020

The rapid growth of smartphone-to-Internet of Things (IoT) connections and the explosive demand for data usage centered on mobile video are increasing day by day, and this increase in data usage creates many problems in the IP system. In a full-based environment, in which information requesters focus on information providers to receive information from specific servers, problems arise with bottlenecks and large data processing. To address this problem, CCN networking technology, a future network technology, has emerged as an alternative to CCN networking technology, which reduces bottlenecks that occur when requesting popular content through caching of intermediate nodes and increases network efficiency, and can be applied to military information and communication networks to address the problem of traffic concentration and the use of various surveillance equipment in full-based networks, such as scientific monitoring systems, and to provide more efficient content.

• Journal of KIISE
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• v.44 no.10
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• pp.1005-1018
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• 2017

Recently, virtualization has become an essential component of cloud computing due to its various strengths, including maximizing server resource utilization, easy-to-maintain software, and enhanced data protection. However, since virtualization allows sharing physical resources among the VMs, the system performance can be deteriorated due to device contentions. In this paper, we first investigate the I/O overhead based on the number of VMs on the same server platform and analyze the block I/O process of the KVM hypervisor. We also propose an in-memory block cache mechanism, called QBic, to overcome I/O virtualization latency. QBic is capable of monitoring the block I/O process of the hypervisor and stores the data with a high access frequency in the cache. As a result, QBic provides a fast response for VMs and reduces the I/O contention to physical devices. Finally, we present a performance measurement of QBic to verify its effectiveness.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.219-230
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• 2003

Motion capture technology is widely used to make a realistic motion in these days. So, motion capture data is required to exchange between many animators in a work group. But different motion capture devices have different motion rapture data formats. Thus it is difficult that a animator reuse and exchange motion capture data in a storage. In this paper, we proposes a standard format for integrating a different motion capture data format. In addition, we proposes a framework of a system that manage motion capture data using our standard format. Our standard format is called MCML(Motion Capture Markup Language). It is a markup language for motion capture data and based on XML(extensable Markup Language). Our system to manage motion capture data consists of a several component - MCML Converter, MCML , MCML Editor, Motion Viewer.