• 한국측량학회지
• /
• 제35권2호
• /
• pp.113-122
• /
• 2017

Natural disasters caused by climate change are increasing globally. There are few studies on the quantitative analysis methods for predicting damages in the island area due to sea level rise. Therefore, it is necessary to study the damage prediction analysis method using the GIS which can quantitatively analyze. In this paper, we analyze the cause and status of sea level rise, quantify the vulnerability index, establish an integrated terrestrial modeling method of the ocean and land, and establish a method of analyzing the damage area and damage scale due to sea level rise using GIS and the method of making the damage prediction figure was studied. In order to extract the other affected areas to sea level rise are apart of the terrain model is generated by one requires a terrain modeling of target areas are offshore and vertical reference system differences in land, found the need for correction by a tidal observations and geoid model there was. Grading of terrain, coastline erosion rate, coastal slope, sea level rise rate, and even average by vulnerable factors due to sea level rise indicates that quantitative damage prediction is possible due to sea level rise in the island area. In the case of vulnerable areas extracted by GIS, residential areas and living areas are concentrated on the coastal area due to the nature of the book area, and field survey shows that coastal changes and erosion are caused by sea level rise or tsunami.

• 한국항행학회논문지
• /
• 제17권5호
• /
• pp.475-483
• /
• 2013

본 논문에서는 Network RTK 보정정보를 사용자에 적용 시, 다중 기준국 보정정보 모델링 방식에 따른 사용자 성능 비교를 수행하였다. 기준국과 사용자 거리가 멀어질수록 사용자와 기준국의 GPS 오차요소 상관성이 감소하므로, 이와 같은 GPS 오차요소의 공간적 특성에 입각하여 다수의 네트워크 보정정보를 적절히 조합하여 사용자에 적용해주어야 한다. 기존에 기준국간 수평 거리 및 고도를 활용한 다양한 보정정보 모델링 방식을 활용하여, MAC 방식의 Compact Network RTK에 적용 가능한지 이론적으로 분석하였다. 한국 내 설치된 상시 기준국에서 습득한 실측 GPS 데이터를 활용하여, 서울대학교에서 제안한 Compact RTK와 기존의 Network RTK가 결합된 방식인 Compact Network RTK 사용자에 대해 각 모델링 방식 별 사용자 성능을 측정치 잔여오차 및 위치 정확도 예측치 관점에서 비교 및 분석을 수행하였다. 그 결과, 각 보정정보 모델링 방식에 대해 사용자 수평 위치 정확도 예측치의 경우 모두 2DRMS 5 cm 이내의 정확도를 보였고, 수직 위치 정확도 예측치의 경우 모두 95 % 신뢰도로 7 cm 이내의 정확도를 나타내었다. 또한, 기존 보정정보 모델 방식 중, 기준국간 고도 차이를 사용한 모델링 방법의 적용 가능 기준국 배치 조건에 대해 분석하였다.

• 전기학회논문지
• /
• 제66권1호
• /
• pp.40-47
• /
• 2017

In this paper, a small signal model for grid-connected inverter with unipolar pulse width modulation method is presented. Small-signal analysis allows to predict the stability and dynamics of the inverter. To regulate output voltage and to achieve power factor correction, inverter has two control loops. Loop gains are useful to identify the stability for multi-loop controlled system. Based on small-signal model, controllers are designed to improve audio susceptibility and output impedance characteristics. Proposed small-signal model and controllers are verified by PSIM simulation and experiments.

• 대한음성학회지:말소리
• /
• 제46호
• /
• pp.51-64
• /
• 2003

In order to produce high quality synthesized speech, it is very important to get an accurate grapheme-to-phoneme conversion and prosody model from texts using natural language processing. Robust preprocessing for non-Korean characters should also be required. In this paper, we analyzed Korean texts using a morphological analyzer, part-of-speech tagger and syntactic chunker. We present a new grapheme-to-phoneme conversion method for Korean using a hybrid method with a phonetic pattern dictionary and CCV (consonant vowel) LTS (letter to sound) rules, for unlimited vocabulary Korean TTS. We constructed a prosody model using a probabilistic method and decision tree-based method. The probabilistic method atone usually suffers from performance degradation due to inherent data sparseness problems. So we adopted tree-based error correction to overcome these training data limitations.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
• /
• pp.167-172
• /
• 2007

The frequency-domain small-loop electromagnetic (EM) instruments are increasingly used for shallow environmental and geotechnical surveys because of their portability and speed. However, it is well known that the data quality is generally so poor that quantitative interpretation of the data is not justified in many cases. We present an inversion method that allows the correction for the calibration errors and also constructs multidimensional resistivity models. The key point in this method is that the data are collected at least at two different heights. The forward modeling used in the inversion is based on an efficient 3-D finite-difference method, and its solution was checked against 2-D finite-element solution. The synthetic and real data examples demonstrate that the joint inversion recovers reliable resistivity models from multi-frequency data severely contaminated by the calibration errors.

• 한국BIM학회 논문집
• /
• 제10권4호
• /
• pp.89-97
• /
• 2020

The purpose of this study is to identify the problems of the currently used 3D spatial information utilization system to realize a more accurate landscape and to establish a user-oriented environment to improve the utilization plan for future landscape evaluation. As citizens' interest in urban landscapes with strong public characteristics increases and the speed of urban development also increases, more suitable simulation methods for landscape management are required. Nevertheless, there are many cases of inconvenient correction according to development changes along with many errors in various steps for creating landscape simulation. Therefore, in performing landscape deliberation according to development, it is necessary to create more accurate and efficient landscape simulation, and if changes occur after the initial deliberation, a process that can quickly and conveniently correct and supplement data is needed. In addition, it is necessary to create landscape simulation so that the created modeling source can be used by being compatible with other application programs. In this study, a method of constructing a more accurate and efficient simulation at the time of initial deliberation and a method of creating a landscape simulation model for rapid response to a plan that is changed at the time of re-deliberation are described.

• 대한원격탐사학회지
• /
• 제24권5호
• /
• pp.483-496
• /
• 2008

Qualified ground control points (GCPs) are required to construct a digital elevation model (DEM) from a pushbroom stereo pair. An inverse geolocation algorithm for extracting GCPs from ERS SAR data and the SRTM DEM was recently developed. However, not all GCPs established by this method are accurate enough for direct application to the geometric correction of pushbroom images such as SPOT, IRS, etc, and thus a method for selecting and removing inaccurate points from the sets of GCPs is needed. In this study, we propose a method for evaluating GCP accuracy and winnowing sets of GCPs through orientation modeling of pushbroom image and validate performance of this method using SPOT stereo pair of Daejon City. It has been found that the statistical distribution of GCP positional errors is approximately Gaussian without bias, and that the residual errors estimated by orientation modeling have a linear relationship with the positional errors. Inaccurate GCPs have large positional errors and can be iteratively eliminated by thresholding the residual errors. Forty-one GCPs were initially extracted for the test, with mean the positional error values of 25.6m, 2.5m and -6.1m in the X-, Y- and Z-directions, respectively, and standard deviations of 62.4m, 37.6m and 15.0m. Twenty-one GCPs were eliminated by the proposed method, resulting in the standard deviations of the positional errors of the 20 final GCPs being reduced to 13.9m, 8.5m and 7.5m in the X-, Y- and Z-directions, respectively. Orientation modeling of the SPOT stereo pair was performed using the 20 GCPs, and the model was checked against 15 map-based points. The root mean square errors (RMSEs) of the model were 10.4m, 7.1m and 12.1m in X-, Y- and Z-directions, respectively. A SPOT DEM with a 20m ground resolution was successfully constructed using a automatic matching procedure.

• 한국소음진동공학회논문집
• /
• 제24권7호
• /
• pp.537-548
• /
• 2014

In this paper, horn loudspeaker modeling was suggested, investigated and verified through comparison of test results and simulation ones based on input electrical impedance curves and acoustic sensitivity ones. First, Thiele Small parameters of horn driver were identified by using pseudo loudspeaker model concept and verified in case of both closed and open horndriver. Second, cone-shaped horn models were investigated and compared with input acoustic impedance curves for real horn(cone angle $6.6^{\circ}$) and short horn(cone angle $27.9^{\circ}$). It showed that Leach model for cone horn was well described to test results, which were electrical impedance and acoustic sensitivity, compared to Lemaitre one. To represent horn system model good approximation in wide frequency range, mass correction filter and lowpass filter were adopted and consequently showed good fitted to test results.

• Journal of Positioning, Navigation, and Timing
• /
• 제12권1호
• /
• pp.67-73
• /
• 2023

As interest in underwater structures and ocean exploration increases, many researchers are proposing methods for modeling and controlling various remotely operated vehicles (ROVs). Recently, hybrid systems composed of an autonomous underwater vehicle and an ROV capable of remote control and autonomous navigation are being developed. In this study we introduce a method that models Ariari-aROV, an ROV consisting of five thrusters, and performs navigation. The proposed ROV can be controlled manually and by autonomous navigation when given a target point. An extended Kalman filter is utilized for sensor measurement correction for more precise navigation. The proposed method is verified through a simulation.

• 지구물리와물리탐사
• /
• 제10권2호
• /
• pp.154-160
• /
• 2007

이 논문에서는 Mackie et al. (1994), Sasaki (1999) 및 Nam et al. (2007)이 개발한 3차원 자기지전류 탐사 모델링 알고리듬의 특징을 자세히 비교 분석하고자 한다. Mackie et al. (1994)과 Sasaki (1999)의 알고리듬은 유한차분법(FDM)에 기초한 반면, Nam et al. (2007)의 알고리듬은 변유한요소법(EFEM)에 기초하고 있다. 이들 세 가지 방법으로 COMMEMI 3D-2 모형의 해를 구하고 적분방정식법의 해와 비교하였으며, 또한 세 가지 격자에 대해 세 개 주파수에서 계산시간을 비교하였다. FDM에 기반을 둔 두 가지 기법에서는 EFEM을 이용하는 경우보다 빠른 시간에 해를 계산할 수 있으며 이때 계산된 겉보기비저항과 위상은 전체적으로 적분방정식법의 해와 잘 일치하였으며 이상체 근처에서만 작은 차이를 보인다. 한편 EFEM에 기초한 알고리듬도 비교적 합리적인 시간 내에 매우 정확한 해를 계산할 수 있으며 지형을 포함한 경우에도 해를 계산할 수 있는 장점이 있다.