• 한국국방경영분석학회지
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• 제34권3호
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• pp.53-66
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• 2008

NCW 개념을 구현하기 위해서는 센서격자망(Sensor Grid)과 타격격자망(Shooter Grid)을 네트워크로 연결하는 정보격자망 구축이 핵심이다. 미 국방부는 정보격자망 개념을 국방 전 임무영역을 연결하는 GIG(Global Information Grid, 범세계 정보격자망)개념으로 발전시켰고, 이를 점진적으로 구축하고 있다. 이러한 관점에서 미 국방부 GIG구축 사례는 한국적 GIG 개념을 정립하는데 있어서 참고할 수 있다. 따라서 본 논문에서는 미 국방부 GIG 구축 동향과 한국군의 GIG 구축 현황을 분석하였고, 이를 근간으로 한국군의 GIG 구축 방향을 제시하였다.

• Journal of Information Processing Systems
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• 제2권2호
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• pp.101-106
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• 2006

Grid computing is an emerging technology that enables global resource sharing. In Korea, the $K^*$Grid provides an extremely powerful research environment to both industries and academia. As part of the $K^*$Grid project, we have constructed, together with the Korea Institute of Science and Technology Information and a number of domestic universities, a supercomputer Grid test bed which connects several types of supercomputers based on the globus toolkit. To achieve efficient networking in this Grid testbed, we propose a novel method of available bandwidth measurement, called Decoupled Capacity measurement with Initial Gap (DCIG), using packet trains. DCIG can improve the network efficiency by selecting the best path among several candidates. Simulation results show that DCIG outperforms previous work in terms of accuracy and the required measurement time. We also define a new XML schema for DCIG request/response based on the schema defined by the Global Grid Forum (GGF) Network Measurement Working Group (NM-WG).

• 한국군사과학기술학회지
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• 제13권2호
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• pp.180-187
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• 2010

In this paper, a global path generation method is suggested using multiple grid maps connected with the mission type of unmanned combat vehicle(UCV). In order to carry out a mission for UCV, it is essential to find a global path which is coincident with the characteristics of the mission. This can be done by considering various combat circumstances represented as grid maps such as velocity map, threat map and communication map. Cost functions of multiple grid maps are linearly combined and normalized to them simultaneously for the path generation. The proposed method is realized using $A^*$, a well known search algorithm, and cost functions are normalized in the ratio of the traverse time which is one of critical information should be provided with the operators using the velocity map. By the experiments, it is checked found global paths match with the mission type by reflecting input data of grid maps properly and the computation time is short enough to regenerate paths in real time as combat circumstances change.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.575-591
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• 2006

In a previous research, we presented the Grid Method and confirmed it as a systematic and efficient problem formulation method for the task-oriented design of robot kinematics. However, our previous research was limited in two ways. First, it gave only a local optimum due to its use of a local optimization technique. Second, it used constant weights for a cost function chosen by the manual weights tuning algorithm, thereby showing low efficiency in finding an optimal solution. To overcome these two limitations, therefore, this paper presents a global optimization technique and an adaptive weights tuning algorithm to solve a formulated problem using the Grid Method. The efficiencies of the proposed algorithms have been confirmed through the kinematic design examples of various robot manipulators.

• 한국재난정보학회 논문집
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• 제17권1호
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• pp.25-38
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• 2021

연구목적: 지속적으로 발생하는 태풍의 피해를 감소시키기 위해 태풍대응의 예방·대비 단계에서 적극적으로 활용할 수 있도록 표준화된 격자의 활용방안을 제안하였다. 태풍위험지역에 대한 격자 융합정보를 시범적으로 생성함으로써 태풍대응을 위한 격자의 실효성을 확인한다. 연구방법: 태풍 상황대응 시 유용하게 사용될 수 있는 태풍 위험지역에 대한 융합정보를 생성하기 위해 vector, raster 등 다양한 형태의 원천데이터를 사용하여 세밀한 공간 단위로 태풍 위험지역 격자 정보를 구축하였다. 기구축된 정보들과의 호환성 및 각 지자체별로 생성되는 격자 정보의 호환성을 위해 표준화된 격자모델을 적용하였다. 연구결과: 국가지점번호의 격자체계를 적용하여 태풍상황대응시 유용하게 활용될 수 있는 태풍위험지역 격자를 구축하였다. 국가지점번호 격자체계는 다차원 계층구조의 격자크기를 정의하고 있으며, 100m와 1,000m 크기의 격자를 활용하여 서울지역 태풍위험지역 격자를 구축하였다. 결론: 다양하고 조밀한 공간정보를 하나의 격자정보로 융합하여 가시화함으로써 재난 의사결정을 위한 정보의 단순화를 통해 신속한 재난대응을 지원할 수 있다.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2004년도 e-Biz World Conference
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• pp.37-42
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• 2004

Information Quality Challenge ·Incomplete business process ·Islands of data ·Escalating costs ·No planned information architecture(omitted)

• 한국군사과학기술학회지
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• 제16권5호
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• pp.583-589
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• 2013

In this paper, we proposed a system that efficiently provides support maps which includes the grid based terrain analysis information. To do this, we use the FDB which is defined as a GIS database that contains features with attributes attached to the features. The FDB is composed of a number of features and feature classes. In order to create support maps, it is necessary to classify feature classes that are associated with each support map and to search them in a grid map. The proposed system use a ontology model to classify semantically feature classes and the quad-tree data structure to find them in a grid map quickly. Therefore, our system is expected to be utilized for global path planning of UGV. In this paper, we show the possibility through an experimental implementation.

• 대기
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• 제30권2호
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• pp.155-167
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• 2020

In order to produce more detailed and accurate information of river discharge and freshwater discharge, global high-resolution hydrodynamic model (CaMa-Flood) is applied to an operational land surface model of global seasonal forecast system. In addition, bias correction to grid runoff for the hydrodynamic model is attempted. CaMa-Flood is a river routing model that distributes runoff forcing from a land surface model to oceans or inland seas along continentalscale rivers, which can represent flood stage and river discharge explicitly. The runoff data generated by the land surface model are bias-corrected by using composite runoff data from UNH-GRDC. The impact of bias-correction on the runoff, which is spatially resolved on 0.5° grid, has been evaluated for 1991~2010. It is shown that bias-correction increases runoff by 30% on average over all continents, which is closer to UNH-GRDC. Two experiments with coupled CaMa-Flood are carried out to produce river discharge: one using this bias correction and the other not using. It is found that the experiment adapting bias correction exhibits significant increase of both river discharge over major rivers around the world and continental freshwater discharge into oceans (40% globally), which is closer to GRDC. These preliminary results indicate that the application of CaMa-Flood as well as bias-corrected runoff to the operational global seasonal forecast system is feasible to attain information of surface water cycle from a coupled suite of atmospheric, land surface, and hydrodynamic model.

• Journal of Power Electronics
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• 제16권5호
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• pp.1939-1949
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• 2016

This paper presents an alternative frequency adaptive grid synchronization technique named HDN-FLL, which can accurately extract the fundamental positive- and negative-sequence components and interested harmonics in adverse three-phase grid voltage. The HDN-FLL is based on the harmonic decoupling network (HDN) consisting of multiple first order complex vector filters (FOCVF) with a frequency-locked loop (FLL), which makes the system frequency adaptive. The stability of the proposed FLL is strictly verified to be global asymptotically stable. In addition, the linearization and parameters tuning of the FLL is also discussed. The structure of the HDN has been widely used as a prefilter in grid synchronization techniques. However, the stability of the general HDN is seldom discussed. In this paper, the transfer function expression of the general HDN is deduced and its stability is verified by the root locus method. To show the advantages of the HDN-FLL, a simulation comparison with other gird synchronization methods is carried out. Experimental results verify the excellent performance of the proposed synchronization method.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1586-1592
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• 2017

Voltage sourced converter (VSC) based direct-current (DC) grid has the ability to control power flow flexibly and securely, thus it has become one of the most valid approaches in aspect of large-scale renewable power generation, oceanic island power supply and new urban grid construction. To solve the optimal power flow (OPF) problem in DC grid, an adaptive particle swarm optimization (PSO) algorithm based on fuzzy control theory is proposed in this paper, and the optimal operation considering both power loss and voltage quality is realized. Firstly, the fuzzy membership curve is used to transform two objectives into one, the fitness value of latest step is introduced as input of fuzzy controller to adjust the controlling parameters of PSO dynamically. The proposed strategy was applied in solving the power flow issue in six terminals DC grid model, and corresponding results are presented to verify the effectiveness and feasibility of proposed algorithm.