• Journal of IKEEE
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• v.26 no.4
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• pp.577-583
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• 2022

Verilog-HDL-based modeling can be performed to confirm the fast operation characteristics after setting the design parameters of each block considering the stability of the system by performing linear phase-domain modeling on the phase-locked loop. This paper proposed Verilog-HDL modeling including DCO noise and DTC nonlinear characteristic. After completing the modeling, the time-domain transient simulation can be performed to check the feasibility and the functionality of the proposed PLL system, then the phase noise result from the system design based on the functional model can be verified comparing with the ideal phase noise graph. As a result of the comparison of simulation time (6 us), the Verilog-HDL-based modeling method (1.43 second) showed 484 times faster than the analog transistor level design (692 second) implemented by TSMC 0.18-㎛.

• Smart Media Journal
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• v.2 no.2
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• pp.28-32
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• 2013

In this paper, we present a method to reduce complexity of depth modeling modes (DMM) that are used in the current 3D-HEVC standardization. DMM adds four modes to the existing HEVC intra prediction modes for accurate object edge representation in the depth map. Especially, Mode 3 requires distortion calculation of numerous pre-defined wedgelets, inducing high complexity. The proposed method employs absolute differences of neighboring pixels in the sides of the reference block to find high intensity changing positions. Based on such positions, the number of wedgelet candidates is reduced to six and distortion calculation is skipped for irrelevant wedgelets. Experimental results show complexity reduction by 3.1% on average, while maintaining similar coding performance.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.81-84
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• 2007

This paper describes general procedure and results of the GPS 3rd odor network adjustment which has been carried out for determining coordinates sets with respect to new Korean Geodetic Datum, so-call Korean Geodetic Datum 2002 (KGD 2002). The adjustment begins with minimally constrained adjustments with respect to each of the 69 campaign networks. This was followed by constructing and adjusting sixteen block network. After detecting and removing outliers in the observation file, an attempt was made by applying the empirical stochastic modeling techniques used in the 2nd order network adjustment, so as to determine the magnitude of absolute and relative error for the estimated baseline vector from the GPS data processing. The over constrained adjustment were, in sequence, performed against each of the block network. In this adjustment, both of the 2nd order control points in the block network and the 3rd order control points overlapped with adjacent network whose coordinates were already determined from a preceding adjustment. The final adjustment results have shown that the accuracy of the 3rd order network adjustment was better than 1cm and 2cm in horizontal and vertical component, respectively.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.2
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• pp.139-151
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• 1997

An ATM switching system may be designed so that communications between processors of its control part can be performed via its switching network rather than a separate inter-processor communications (IPC) network. In such a system, there should be interfaces to convent IPC traffic from message format to cell format and vice versa, that is, mechanisms to perform the SAR (Segmentation And Reassembly) sublayer functions. In this paper, we concern the cell reassembly mechanism among them, mainly focussed on buffer management schemes. We consider a few alternatives to implement cell reassembly function block, namely, separated buffering, reserved buffering and shared buffering in this paper. In case of separated and reserved buffering, we employ a continuous time Markov chain for the performance evaluation of cell reassembly mechanism, judicially defining the states of the mechanism. Performance measures such as measage loss probability, mean number of message queued in buffer and average reassembly delay are obtianed in closed forms. In case of shared buffering, we compare the alternatives for implementing cell reassembly function block using simulation because it is almost impossible to analyze the mechanism of shared buffering by analytical modeling. Some illustrations are given for the performance analysis of the alternatives to implement cell reassembly function block.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.185-190
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• 2007

In this study, we developed the 2.5D EM modeling and inversion algorithm for cross-hole source and receiver geometry. Considering the cross-hole environment, we use a VMD (vertical magnetic dipole) as a source and vertical magnetic fields as a measuring data. Developed inversion algorithm is tested for the isolated block model which has a conductive and a resistivity anomaly respectively. For the conductive anomaly, its size and resistivity are inverted well on the inversion results, while for the resistive anomaly, the location of anomalous block is shown on the inverted section, but its values are far from the exact value. Furthermore, artificial conductive anomalies are shown around the resistive anomalous zone. If we consider the inversion artifact shown in the test inversion of restive block, it is almost impossible to image the resistive zone. However, the main target of EM tomography in the engineering problem is conductive target such as fault zone, and contaminated zone etc., EM tomography algorithm can be used for detecting the anomalous zone.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.927-929
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• 2011

Since DVC (Distributed Video Coding) and FRUC (Frame Rate Up Conversion) techniques need to have an efficient motion compensated frame interpolation algorithms. Conventional works of these applications have mainly focused on the performance improvement of overall system. But, in some applications, it is necessary to evaluate how well the MCI (Motion Compensated Interpolation) frame matches the original frame. For this aim, this paper deals with the modeling methods for evaluating the block-based matching cost. First, several matching criteria, which have already been dealt with the motion compensated frame interpolation, are introduced and then combined to make estimate models for the size of MSE (Mean Square Error) noise of the MCI frame to original one. Through computer simulations, it is shown that the block-based cost evaluation models are tested and can be effectively used for estimating the MSE noise.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.641-649
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• 2009

There were many simulation models that made for validation of industrial environment and estimate of efficiency to be constructed. And there will be more simulation models made for same reason, too. Already, there have been a lot of simulation models in industry field and scholar labs. To reuse these simulation models, it is necessary to find common properties and make the high abstract simulation model. Based on this idea, this study shows to define the high abstract simulation model to be able to specialize in need and to make the software framework for connecting the specific simulation model to the abstract model. And it is held up as the example that applying the simulation framework to the Ship Panel Block shop simulation model.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.42-52
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• 1997

Computer aided process planning and Offline programming are decisive factors in successful implementation of automated robotic production. However, conventional offline programming procedure has proven ineffective due to time-consuming teaching process for robot programming and due to inefficient system modeling. The paper presents an efficient procedure to semi-automatically generate robot job programs for ship block welding applications. In the research, the teaching positions are automatically determined by predefined rules which are functions of the type and the dimensions of the given welding section of ship block. And a sequence of robot movements and welding conditions such as welding type, welding current, welding speed, and welding torch orientation, are determined by use of Standard Program which is experimentally proved to work well for the welding wection group. Finally, a robot program for the welding section is generated automatically. Based on the algorithm, a offline automatic teaching software is developed. The paper presents also the algorithm and structure of the software.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.187-194
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• 2002

본 논문에서는 SPOT 입체영상을 이용하여 광범위한 지역의 DEM을 제작할 경우 DEM 모자이크 과정에서 발생할 수 있는 접합선(seam-line)을 최소화할 수 있는 방법을 연구하였다. 지상의 60km$\times$60km 영역을 촬영할 수 있는 SPOT 위성의 입체 영상으로부터 구성한 단일 모델은 일반적으로 관심 있는 지역의 DEM을 제작하기에 충분히 넓은 지역을 포함할 수 있다. 그러나 광범위한 지역의 DEM 제작을 위해서는, 각각의 입체영상을 통해 제작된 DEM들을 접합해야 하며, 이 때 발생되는 접합선을 효과적으로 제거하는 작업이 필요하다. 이를 위해 SPOT 위성영상의 블록 조정 방법을 이용하여 종횡접합모델을 구성하고 중복되는 인접한 SPOT DEM간의 표고값을 일치시키므로써 DEM 접합선의 발생을 최소화하여 모자이크시 작업량을 줄이고자 한다. 본 논문에서는 기존의 지상기준점과 추가로 관측한 영상접합점을 이용하여 종횡접합 블록을 구성하고 광속조정 방법을 적용하여 블록에 포함된 위성영상의 외부표정요소를 계산하였다. 블록모델을 이용하여 DEM을 제작할 경우 접합선 탐색 및 blending 작업 없이 단순중첩 방법으로도 DEM 모자이크 작업을 빠르게 수행할 수 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1201-1204
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• 2004

This paper suggests a DCS (Distributed Control System) model for steam temperature system of the thermal power plant. The model calculated within sectional range is linear. In order to calculate mathematical models, the system is partitioned into two or three sectors according to its thermal conditions, that is, saturated water/steam and superheating state. It is divided into three sections; water supply, steam generation and steam heating loop. The steam heating loop is called 'superheater' or steam temperature system. Water spray supply is the control input. A first order linear model is extracted. For linear approach, sectional linearization is achieved. Modeling methodology is a decomposition-synthetic technique. Superheater is composed of several tube-blocks. For this block, linear input-output model is to be calculated. Each tiny model has its transfer function. By expanding these block models to total system, synthetic DCS linear models are derived. Control instrument include/exclude models are also considered. The resultant models include thermal combustion conditions, and applicable to practical plant engineering field.