• Journal of Wetlands Research
• /
• v.12 no.3
• /
• pp.67-78
• /
• 2010

Surface sedimentary facies and the change of microphytobenthos distribution in Geunso Bay tidal flat were monitored using remotely sensed data. Sediment distribution was analyzed along with the spectral reflectance based on the in situ data, and the spectral characteristics of the area where microphytobenthos occupied was examined. A medium to low spatial resolution of satellite image was not suitable for the detection of the surface sediments changes in the study area due to its ambiguity in the sedimentary facies boundary, but the seasonal changes of microphytobenthos distribution could be obviously detected. However, area of predominance of sand grains and seagrass distribution could be distinctly identified from a high spatial resolution remote sensing image. From this, it is expected that KOMPSAT-2 satellite images can be applied effectively to the study on the surface sedimentary facies and detailed ecological mapping in a tidal flat.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.2
• /
• pp.239-245
• /
• 2012

This paper proposes a novel optimum design method for the PID controller of magnetic levitation-based Rail-Guided Vehicle(RGV) by a genetic algorithm using clone selection method and a new performance index function with performances of both time and frequency domain. Generally, since an attraction type levitation system is intrinsically unstable and requires a delicate controller that is designed considering overshoot and settling time, it is difficult to completely satisfy the desired performance through the methods designed by conventional performance indexes. In the paper, the conventional performance indexes are analyzed and then a new performance index for Maglev-based RGV is proposed. Also, an advanced genetic algorithm which is designed using clonal selection algorithm for performance improvement is proposed. To verify the proposed algorithm and the performance index, we compare the proposed method with a simple genetic algorithm and particle swarm optimization. The simulation results show that the proposed method is more effective than conventional optimization methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.219-224
• /
• 2017

These days, it is developed renewable energy-based wind power technology. Wind power generation is relatively quiet, and environmental damage is relatively low. In developed countries, a lot of wind power generation is being built. In Korea, the generation efficiency is low because there are few areas where the wind speed is maintained for four seasons. In recent years, forest damage, low noise, and environmental degradation complaints are frequent. In this paper, we performed an experiment to manage pitch control effectively by analyzing wind, direction, and temperature in real time based on FUZZY rule and cluster analysis.Using the new algorithm proposed by the simulation results, we could verify the efficiency of wind power generation pitch control for wind condition and direction condition by using the pitch control analysis technique.Furthermore, visualization representations have proven to automatically analyze early warning and efficiency of generator performance.

• Korean journal of applied entomology
• /
• v.31 no.4
• /
• pp.360-365
• /
• 1992

Leaf feeding insect species of welsh onion and shallot were surveyed, and their species abundances were analyzed by fitness test for lognomal disstribution. A total of 13 and 6 species were identified on welsh onion and shallot, respectively. The dominant species on welsh onion were Thrips tabacid, Acrolepiopsis sapporensis, Spodoptera exigua, and Liriomyza chinensis. Thrips tabacid was also identified as the major species on the shallot. The community dominance was high in welsh onion and shallot observed on 12 October, Suwon. The species abundance patterns of the two communities were well described by lognormal distribution(P> 0.50).

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1159-1163
• /
• 2010

최근의 극심한 기상이변으로 인하여 발생되는 유출량의 예측에 관한 사항은 치수 이수는 물론 방재의 측면에서도 역시 매우 중요한 관심사로 부각되고 있다. 강우-유출 관계는 유역의 수많은 시 공간적 변수들에 의해 영향을 받기 때문에 매우 복잡하여 예측하기 힘든 요소이다. 과거에는 추계학적 예측모형이나 확정론적 예측모형 혹은 경험적 모형 등을 사용하여 유출량을 예측하였으나 최근에는 인공신경망과 퍼지모형 그리고 유전자 알고리즘과 같은 인공지능기반의 모형들이 많이 사용되고 있다. 하지만 유출량을 예측하고자 할 때 학습자료 및 검정자료로써 사용되는 유출량은 수위-유량 관계곡선식으로부터 구하는 경우가 대부분으로 이렇게 유도된 유출량의 경우 오차가 크기 때문에 그 신뢰성에 문제가 있을 것으로 판단된다. 따라서 본 논문에서는 선행우량 및 수위자료로부터 단시간 수위예측에 관해 연구하였다. 신경망은 과거자료의 입 출력 패턴에서 정보를 추출하여 지식으로 보유하고, 이를 근거로 새로운 상황에 대한 해답을 제시하도록 하는 인공지능분야의 학습기법으로 인간이 과거의 경험과 훈련으로 지식을 축적하듯이 시스템의 입 출력에 의하여 연결강도를 최적화함으로서 모형의 구조를 스스로 조직화하기 때문에 모형의 구조에 적합한 최적 매개변수를 추정할 수 있다. 따라서 정확한 예측이 어려운 하천수위를 과거의 자료로 부터 학습된 신경망의 수학적 알고리즘을 통해 유출량의 예측에 적용할 수 있을 것이다. 유전자 알고리즘은 적자생존의 생물학 원리에 바탕을 둔 최적화 기법중의 하나로 자연계의 생명체 중 환경에 잘 적응한 개체가 좀 더 많은 자손을 남길 수 있다는 자연선택 과정과 유전자의 변화를 통해서 좋은 방향으로 발전해 나간다는 자연 진화의 과정인 자연계의 유전자 메커니즘에 바탕을 둔 탐색 알고리즘이다. 즉, 자연계의 유전과 진화 메커니즘을 공학적으로 모델화함으로써 잠재적인 해의 후보들을 모아 군집을 형성한 뒤 서로간의 교배 혹은 변이를 통해서 최적 해를 찾는 계산 모델이다. 따라서 본 연구에서는 인공신경망의 가중치를 유전자 알고리즘에 의해 최적화시킨후 오류역전파알고리즘에 의해 신경망의 학습을 진행하는 모형으로 감천유역의 선산수위표지점의 수위를 1시간~6시간까지 예측하였다.

• 한국해양학회지
• /
• v.30 no.2
• /
• pp.138-146
• /
• 1995

Present study was performed to describe the growth of Leptochela gracilis (STIMPSON, 1860), the dominant species of the coastal water near Kanghwa Island, Korea. Samples were collected from 1 sampling point by long bag seine net at monthly interval from April 1993 to January 1994 except for August 1993. In the population study of Leptochela gracilis, ovigerous female has appeared from April to September 1993 and the ratio (egg-bearing female/female) showed over 70% from May to July 1993. Female individuals were predominant from May 1993 to January 1994 and it was found that sex ratios were not significantly different between pregnant and non-pregnant period(p>0.05). The population of Leptochela gracilis was divided into 2 types of generation; i) short term generation. and ii) long term generation. Longevity of the long term generation was presumed to vary from 12 to 15 months. In the case of short term generation, spawned by egg-bearing stock of September, however, it was not certain whether they absorbed in the long term generation, thus overcome winter season or die after December by environment factors. The growth in cavalcade length of the long term generation was better fitted to Pauly and Gaschutz model than Von Bertalanffy.

• Korean Journal of Remote Sensing
• /
• v.19 no.4
• /
• pp.329-339
• /
• 2003

In this study, an approach of image fusion in decision level has been proposed for unsupervised image classification using the images acquired from multiple sensors with different characteristics. The proposed method applies separately for each sensor the unsupervised image classification scheme based on spatial region growing segmentation, which makes use of hierarchical clustering, and computes iteratively the maximum likelihood estimates of fuzzy class vectors for the segmented regions by EM(expected maximization) algorithm. The fuzzy class vector is considered as an indicator vector whose elements represent the probabilities that the region belongs to the classes existed. Then, it combines the classification results of each sensor using the fuzzy class vectors. This approach does not require such a high precision in spatial coregistration between the images of different sensors as the image fusion scheme of pixel level does. In this study, the proposed method has been applied to multispectral SPOT and AIRSAR data observed over north-eastern area of Jeollabuk-do, and the experimental results show that it provides more correct information for the classification than the scheme using an augmented vector technique, which is the most conventional approach of image fusion in pixel level.

• Convergence Security Journal
• /
• v.19 no.2
• /
• pp.3-9
• /
• 2019

Most of security countermeasures have been implemented to cope with continuous increase leakage of technology, but almost security countermeasures are focused on securing the boundary between inside and outside. This is effective for detecting and responding to attacks from the outside, but it is vulnerable to internal security incidents. In order to prevent internal leakage effectively, this study identifies activities corresponding to technology leakage activities and designes technology leakage activity detection items. As a design method, we analyzed the existing technology leakage detection methods based on the previous research and analyzed the technology leakage cases from the viewpoint of technology leakage activities. Through the statistical analysis, the items of detection of the technology leakage outcomes were verified to be appropriate, valid and reliable. Based on the results of this study, it is expected that it will be a basis for designing the technology leaking scenarios based on future research and leaking experiences.

• Korean Journal of Ecology and Environment
• /
• v.52 no.3
• /
• pp.231-244
• /
• 2019

Zooplankton is essential biological assemblage in understanding the structure and function of aquatic ecosystems, since it plays as a linkage between primary producers and higher trophic level organisms such as fish. Although zooplankton has planktonic characteristics, the sampling and treatment methods for its community analyses are more complicated and variable compared with phytoplankton due to its high diversity in body size and species-specific depth selection behaviors. In the present paper, we reviewed representative classical methods for field sampling and treatments of freshwater zooplankton in relation with quantification of its community structure, and suggested appropriate methods depending on various research objectives.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.1
• /
• pp.21-26
• /
• 2019

This paper examines effect of fitness between innovation and HRM type on firm performance(quality competitiveness, operating profit). Data were extracted from the Korea Labor Institute's workplace panel survey(WPS) from 2015, and the analysis used 3,431 companies. To test the research model, analysis of variance(ANOVA). The model shows that full-innovation/commitment HRM type companies were significantly higher quality competitiveness, and operating profit than other companies. And low-level innovation/control HRM type companies were significantly lower quality competitiveness and operating profit than other companies.