• 한국측량학회지
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• 제38권2호
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• pp.153-163
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• 2020

After launching the GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) which obtains high-frequency gravity signal using a gravity gradiometer, many research institutes are concentrating on the development of GGM (Global Geopotential Model) based on GOCE data and evaluating its precision. The precision of some GGMs was also evaluated in Korea. However, some studies dealt with GGMs constructed based on initial GOCE data or others applied a part of GNSS (Global Navigation Satellite System) / Leveling data on UCPs (Unified Control Points) for the precision evaluation. Now, GGMs which have a higher degree than EGM2008 (Earth Gravitational Model 2008) are available and UCPs were fully established at the end of 2019. Thus, EIGEN-6C4 (European Improved Gravity Field of the Earth by New techniques - 6C4), GECO (GOCE and EGM2008 Combined model), XGM2016 (Experimental Gravity Field Model 2016), SGG-UGM-1, XGM2019e_2159 were collected with EGM2008, and their precisions were assessed based on the GNSS/Leveling data on UCPs. Among GGMs, it was found that XGM2019e_2159 showed the minimum difference compared to a total of 5,313 points of GNSS/Leveling data. It is about a 1.5cm and 0.6cm level of improvement compare to EGM2008 and EIGEN-6C4. Especially, the local biases in the northern part of Gyeonggi-do, Jeju island shown in the EGM2008 was removed, so that both mean and standard deviation of the difference of XGM2019e_2159 to the GNSS/Leveling are homogeneous regardless of region (mountainous or plain area). NGA (National Geospatial-Intelligence Agency) is currently in progress in developing EGM2020 and XGM2019e_2159 is the experimentally published model of EGM2020. Therefore, it is expected that the improved GGM will be available shortly so that it is necessary to verify the precision of new GGMs consistently.

• 한국컴퓨터정보학회논문지
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• 제23권8호
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• pp.59-66
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• 2018

In this paper we purposes to analyze the motivation of mobile payment adopters. In this study, with unified theory of acceptance and use of technology (UTAUT) model as the basis of research, we set up a structural equation model based on gender, age, experience and voluntary, collected data in the form of a questionnaire survey and analyzed drivers that affected mobile payers. In this study, The necessity of this paper is that the group of Korean students belongs to a special group with nearly 70,000 people. The penetration rate of mobile payment in China is 77%, ranking first in the world, but after the young people came to Korea. There are many obstacles and inconveniences when using mobile payment. We have proposed special subjects for special populations. the survey data were analyzed using SPSS22.0 and AMOS22.0 statistical software and the proposed model was modified. The results show that consumers' mobile payment is mainly motivated by social influence and performance expectancy. These results are of theoretical value and offer a new direction and implications to mobile payment developers. Besides, they also provide useful information and guidance for enterprises to aim at the market of Chinese oversea students in South Korea.

• Journal of Information Technology Applications and Management
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• 제10권1호
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• pp.111-125
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• 2003

This paper proposes a product data model that can express and enforce integrity constraints on product structure during engineering changes (ECs). The model adopts and extends an active object-oriented database model in order to Integrate IC data and their integrity constraints. Tightly integrated with product structure, It will enable designers to maintain and exchange consistent EC data throughout the product life cycle. In order to properly support operations for ECs, the model provides the data, operations, and Event-Condition-Action rules for nested ECs and simultaneous EC applications to multiple options. in addition, the EC objects proposed In the model integrate the data and Integrity constraints into a unified repository. This repository enables designers to access all EC data and integrity constraints through the product structure and relationships between EC objects. This paper also describes a prototype product data management system based on the proposed model In order to demonstrate its effectiveness.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.233-244
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• 2016

Smart grid is called it as a system of systems. There are diverse types of systems in smart grid environment. Therefore, one of key factors to achieve smart grid successfully is interoperability among diverse systems. To secure interoperability, smart grid operating system should be developed complied with standards in terms of the data representation and communication. Common Information Model (CIM) and OLE Process for Control - Unified Architecture (OPC-UA) are the representative international standards in smart grid domain. Each standard defines data representation and communication by providing common information model and the unified architecture. In this paper, we explain a smart grid platform that we have developed to comply with CIM and OPC-UA standards for secure interoperability among numerous legacy systems.

• 천문학회보
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• 제42권1호
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• pp.39.1-39.1
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• 2017

Protoplanetary disks (PPDs) are a natural consequence of star formation and play crucial roles in planet formation. Atacama Large Millimeter/submillimeter Array (ALMA) has provided sub-mm data for the PPDs with a high angular resolution and sensitivity, and it makes us enable to study PPDs in detail. We have developed Packages of Unified modeling for Radiative transfer, gas Energetics, and Chemistry (PUREC), which consists of a self-consistent thermo-chemical model and line and continuum radiative transfer models, in order to interpret and predict the ALMA observations for PPDs. In this talk, we introduce capabilities of PUREC.

• 대기
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• 제21권1호
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• pp.85-93
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• 2011

UK Met Office Unified Model (UM) is a grid model applicable for both global and regional model configurations. The Met Office has developed a 4D-Var data assimilation system, which was implemented in the global forecast system on 5 October 2004. In an effort to improve its Numerical Weather Prediction (NWP) system, Korea Meteorological Administration (KMA) has adopted the UM system since 2008. The aim of this study is to provide the basic information on the effects of satellite data assimilation on UM performance by conducting global satellite data denial experiments. Advanced Tiros Operational Vertical Sounder (ATOVS), Infrared Atmospheric Sounding Interferometer (IASI), Special Sensor Microwave Imager Sounder (SSMIS) data, Global Positioning System Radio Occultation (GPSRO) data, Air Craft (CRAFT) data, Atmospheric Infrared Sounder (AIRS) data were assimilated in the UM global system. The contributions of assimilation of each kind of satellite data to improvements in UM performance were evaluated using analysis data of basic variables; geopotential height at 500 hPa, wind speed and temperature at 850 hPa and mean sea level pressure. The statistical verification using Root Mean Square Error (RMSE) showed that most of the satellite data have positive impacts on UM global analysis and forecasts.

• 대한조선학회논문집
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• 제34권4호
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• pp.127-138
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• 1997

본 연구에서는 선박의 기본설계 단계에서 정의된 선도를 입력 정보로 하여 순정도 높은 선형을 표현할 수 있는 기법을 개발하였다. 곡선모델링의 경우, de Casteljau (드 카스텔죠)알고리듬과 Bezier 조정점을 이용하여 자유곡선을 표현하였고, 이를 토대로 Non-Uniform B-Spline(NUB) 곡선, Spline곡선 등으로 서로 변환(Conversion)할 수 있는 Unified curve modeling( 곡선모델링 단일화) 기법을 정립하였다. 곡면모델링의 경우, 곡면정의를 위하여 입력되는 그물망 곡선(Mesh curve net)을 먼저 Unified curve modeling 기법에 의하여 Interpolation(보간)한 후, "Remeshing" (그물망 곡선의 재생성)기법에 의하여 Gregory surface patch(그레고리 곡면 patch)의 Mesh curve segment(경계 세그멘트 곡선)를 생성하고 이를 접속하여 순정도 높은 Composite surface(합성곡면)를 만드는 기법을 개발하였다.

• 한국지구과학회지
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• 제21권6호
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• pp.719-733
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• 2000

요약: 수치지질도는 디지털 포맷으로 지리적인 정보와 연계된 공간 도형정보와 지질학적인 데이터베이스 속성정보를 갖는 지도로 정의가 가능하며, 지질정보의 수치 도면화와 지공간 정보처리가 가능한 두 가지 측면으로 활용될 수 있다. 그러나 지질 정보가 근본적으로 자연현상에 대한 실체와 다양한 원인에 기인한 복합 대상체에 대한 해석을 목적으로 하기 때문에 수치지질도 작업은 기존에 GIS의 주요 응용 분야인 도시정보시스템이나 지도 자동 도면화 등과 같이 인공지물을 다루는 방법을 바로 적용하는 경우 많은 문제점이 있다. 또한 GIS 소프트웨어의 근간을 이루는 정보기술분야의 급속한 발전과 GIS 활용분야의 확대에 따라 각 활용분야의 고유한 특성과 그에 따른 모델은 수치지질정보화에 대한 중요성 요소로 작용하게 된다. 본 연구에서는 이와 관련하여 우선 지질 데이터 모델에 대한 주요한 개념을 설명하고 지질데이터 모델에 대한 그간의 선행연구와 접근 방법을 소개하고자 한다. 또한 최근에 부각되고 있는 객체지향 모델링 방법의 핵심인 UML접근 방법과 이를 이용한 시험적인 모델을 소개하고자 한다. 이러한 접근 방법을 통하여 재사용성을 고려한 개념적인 모델과 이에 상응하는 실용적인 시스템 개발 및 표준화 연구측면에서 기존 방식에 비교하여 많은 장점을 보일 수 있다. 결론적으로 UML 접근방법을 통한 시스템 아키텍처와 이를 기반으로 한 지질정보시스템은 지구과학분야에서 GIS 활용을 위한 새로운 핵심적인 접근방식을 제공하게 될 것으로 예상된다.

• Journal of the Korean Data and Information Science Society
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• 제5권1호
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• pp.21-32
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• 1994

Effects on the scale and location parameters in the exponential model when both parameters changes will be considered, based on the complete or truncated samples by the maximum likelihood and jackknife methods.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.565-565
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• 2013

Free burning arcs where the work piece acts as an anode are frequently used for a number of applications. Our investigation is exclusively concerned with a simplified unified model of arcs and anode under steady state conditions at atmospheric pressure. The model is used to make predictions of arc and anode temperatures and arc voltage for a 200 A arc in argon. The computed temperatures along the axis between the cathode tip and the anode surface compare well the measured data. This knowledge of free burning arcfeatures can play a role in developing the atmospheric plasma systems, however, further investigation should include the modelling of Cu evaporation from anode and non-LTE situation near electrodes for more realistic calculations.