• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.4
• /
• pp.51-57
• /
• 2020

WSN is a wirelessly configured network of sensor nodes with limited power such as batteries. If the sensor node's battery is exhausted, the node is no longer available. Therefore, if the network is to be used for a long time, energy consumption should be minimized. There are many Wireless Sensor Network Protocols to improve energy efficiency, including Cluster-based and chain-based Protocols. This paper seeks to examine the performance evaluation of routing protocols studied separately for the improvement of performance in wireless sensor network. The criteria for comparison were selected as the LEACH protocol, a representative hierarchical routing protocol, and the comparison targets considered CHEF and FLCFP and LEACH-DFL routing protocols with Fuzzy Logic. Various criteria for performance comparison were presented in this paper, and the performance was compared through simulation of each protocol. The purpose is to present a reference point for comparing the performance of other protocols through the performance comparison of CHEF, FLCFP, and LEACH-DFL, protocols with LEACH and Fuzzy Logic, and to provide additional design methods for improving the performance of protocols.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.12 no.5
• /
• pp.467-472
• /
• 2002

In this paper, we propose a Fuzzy Cellular Neural Network(FCNN) that is based on a-Least Trimmed Square Hausdorff distance(a-LTSHD) which applies Hausdorff distance(HD) to the FCNN structure in order to remove the impulse noise of images effectively and also improve the speed of operation. FCNN incorporates Fuzzy set theory to Cellular Neural Network(CNN) structure and HD is used as a scale which computes the distance between set or two pixels in binary images without confrontation of the feature object. This method has been widely used with the adjustment of the object. For performance evaluation, our proposed method is analyzed in comparison with the conventional FCNN, with the Opening-Closing(OC) method, and the LTSHD based FCNN by using Mean Square Error(MSE) and Signal to Noise Ratio(SNR). As a result, the performance of our proposed network structure is found to be superior to the other algorithms in the removal of impulse noise.

• Journal of IKEEE
• /
• v.24 no.1
• /
• pp.9-18
• /
• 2020

The pattern recognition or fuzzy inference, which is mainly used for the development of the automatic walking mode change of the above knee prosthesis, has a disadvantage in that it is difficult to estimate with the immediate change of the walking environment. In order to solve a disadvantage, this paper developed an algorithm that automatically converts the walking mode of the next step by estimating the walking environment at a specific gait phase. Since the proposed algorithm should be implanted and operated in the microcontroller, it is developed using the random forest base in consideration of calculation amount and estimated time. The developed random forest based gait and environmental estimation model were implanted in the microcontroller and evaluated for validity.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.32 no.4
• /
• pp.28-38
• /
• 2004

Korean goral (Nemorhaedus caudatus raddeanus) is one of the endangered species in Korea, and the rugged terrain of the Soraksan National Park (373㎢) is a critical habitat for the species. But the goral population is threatened by habitat fragmentation caused by roads and hiking trails. The objective of this study was to develop a potential habitat suitability model for Korean goral in the park, and the model was based on the concepts of fuzzy set theory and multi-criteria evaluation. The process of the suitability modeling could be divided into three steps. First, data for the modeling was collected by using field work and a literature survey. Collected data included 204 points of GPS data obtained through a goral trace survey and through the number of daily visitors to each hiking trail during the peak season of the park. Second, fuzzy set theory was employed for building a GIS data base related to environmental factors affecting the suitability of the goral habitat. Finally, a multiple-criteria evaluation was performed as the final step towards a goral habitat suitability model. The results of the study were as follows. First, characteristics of suitable habitats were the proximity to rock cliffs, scattered pine (Pinus densiflora) patches, ridges, the elevation of 700∼800m, and the aspect of south and southeast. Second, the habitat suitability model had a high classification accuracy of 93.9％ for the analysis site, and 95.7％ for the validation site at a cut off value of 0.5. Finally, 11.7％ of habitatwith more than 0.5 of habitat suitability index was affected by roads and hiking trails in the park.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.34 no.5 s.118
• /
• pp.39-51
• /
• 2006

This study was carried out to provide guidance to environmental policy makers when deciding which assessment fields (biotic, abiotic, qualitative, functional) should have priority for ecological preservation and to develop an objective and scientific methodology by introducing the engineering concept of the fuzzy integral. The grant of weights was used the eigenvalues calculated by factor analysis, and the converted values of indicators were obtained in multiplying the arithmetic values and eigenvalues. The results of the appropriateness and reliability of assessment fields were examined over 0.6, and the results showed that the design of questionnaire presented no great problems. When the fuzzy integral was calculated to determine the rankings at ${\lambda}$=1, 2, 3, 4, 5, respectively, they were 0.646, 0.630, 0.943, 1.423, and 1.167 for the biotic field, 1.298, 1.400, 0.901, 0.580, and 1.456 for the abiotic field, 0.714, 0.674, 0.346, 0.674, and 1.610 in the qualitative field and 1.000, 0.973, 0.943, 1.024, and 1.008 in the functional field. The sensitivity to ${\lambda}$ value showed that ${\lambda}=4$ was the most suitable. In comparison with ${\lambda}=0$ (the arithmetic mean), the range of change was narrow. Because the range for ${\lambda}=4$ was narrower than my other values, ${\lambda}=4$ was sure to be available in ranking-decision. The fuzzy integral is expected to be a method for analyzing and filtering human thoughts. In the future, in order to overcome linguistic uncertainty and subjectivity, other fuzzy integral models including Sugeno's method, AHP, and so forth should be used.

• Archives of design research
• /
• v.19 no.2 s.64
• /
• pp.81-90
• /
• 2006

Pedestrians perceive differently from the sideway views or the exteriors of the buildings on the way to their destinations. Therefore, the navigation experience can become much different when the path was chosen based on the individual's preference from it is not. By focusing on the effects of the individual pedestrian' path choice on their navigation, this paper presents an algorithm designed for pedestrians to be able to explore their preferred path and proposes a prototype of navigation system based on the algorithm. The navigation support system searches for the best path upon their individual preferences and information of the destination. The system provides the process of retrieving the final path via the pedestrian-support system interaction. The path retrieval is peformed with the combinational matrix of keywords that are formulates Fuzzy theory from the correlations between the terms describing preferences used in the path preference survey. This paper presents the potentials of the path finding method tailored to pedestrians' preferences by a simulation of the proposed path retrieval algorithm.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.128-132
• /
• 2012

물은 생물의 생존을 위해 필수적인 요소로 인류가 시작된 이래로 물을 효율적으로 이용하고 안전하게 관리하기 위한 노력은 계속되어 왔다. 최근 지구 온난화가 주요 원인으로 알려진 국지성 집중호우의 피해는 매우 심각하며, 이로 인해 치수에 대한 중요성은 날로 커지고 있다. 지금까지 사용해 왔던 홍수 예 경보 과정은 특정 지점의 유출량을 예측하기 위해서 강우-유출 모형을 운영하였다. 그러나 물리적 모형의 경우 운영에 필요한 매개변수의 결정과정이 복잡하고, 매개변수 결정을 위해 많은 자료를 필요로 한다. 또한 그 매개변수의 결정과정은 많은 불확실성을 포함하고 있어서 모형의 운영을 위한 전처리과정과 계산과정을 거치는 동안 발생한 오차가 누적되어 결과물 속에는 많은 오차가 포함되어 있다. 본 연구에서는 기존의 홍수 예 경보 시스템의 문제점과 불확실성을 최대한 감소시키고 더 우수한 유출량 예측을 위해 neuro-fuzzy 추론 기법을 이용한 모형인 ANFIS(Adaptive Neuro-Fuzzy Inference System)를 사용하여 하천수위를 예측하였다. ANFIS는 신경회로망과 퍼지이론을 결합한 기법으로 신경회로망의 구조와 학습 능력을 이용하여 제어환경에서 획득한 입 출력 정보로부터 언어변수의 membership 함수와 제어규칙을 제어 대상에 적합하도록 자동으로 조종하는 기법이다. 본 연구에서는 ANFIS를 사용하여 탄천 하류에 위치한 대곡교의 수위를 예측하였다. 분석을 위해 2007년부터 2011년까지의 탄천 유역의 관측 강우자료와 수위 자료 중 강우강도와 지속시간, 강우 형태에 따라 7개의 강우사상을 선정하였다. 학습자료 및 보정자료의 변화에 따른 예측 오차를 비교하여 모형의 적용성과 적정성을 평가하였다. 적용결과 입력자료 구성의 경우 해당 시간의 강우량 및 수위자료와 10분 전 강우자료를 이용한 모델이 가장 우수한 예측을 보였고, 학습자료의 경우 자료의 길이가 길고, 최대홍수량이 큰 경우 가장 우수한 예측 결과를 보였다. 본 연구의 적용결과 가장 우수한 모형의 경우 30분 예측 첨두수위 오차는 0.32%, RMSE는 0.05m 이고 예측시간이 길어짐에 따라 오차가 비선형적으로 증가하는 경향을 보였다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.6
• /
• pp.735-740
• /
• 2012

In this paper, we introduce design methodologies of polynomial radial basis function neural network classifier with the aid of Principal Component Analysis(PCA) and Linear Discriminant Analysis(LDA). By minimizing the information loss of given data, Feature data is obtained through preprocessing of PCA and LDA and then this data is used as input data of RBFNNs. The hidden layer of RBFNNs is built up by Fuzzy C-Mean(FCM) clustering algorithm instead of receptive fields and linear polynomial function is used as connection weights between hidden and output layer. In order to design optimized classifier, the structural and parametric values such as the number of eigenvectors of PCA and LDA, and fuzzification coefficient of FCM algorithm are optimized by Artificial Bee Colony(ABC) optimization algorithm. The proposed classifier is applied to some machine learning datasets and its result is compared with some other classifiers.

• The Journal of shipping and logistics
• /
• v.34 no.4
• /
• pp.657-675
• /
• 2018

This study examines various policy programs for the creation of green harbors in major ports in the Northwest of the United States and suggests ways to apply them to major ports in Korea. Based on the fuzzy analysis process, the importance of major policy programs for the development of green ports in Korea was compared and analyzed. As a result of importance analysis, the Green Ship Incentive Program and the Carbon Footprint Program were identified as the most important policies. The first policy programs that should be introduced to Incheon Port are the AMP installation operation program and a vessel slowing program around the seaport. In case of Busan Port, the AMP installation operation program, the vessel slowing program around the seaport, carbon footprint, and installation of DPF were found to be excellent policies. These results may provide practical implications for policy makers of port authorities which has conducted environmental projects.

• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.373-378
• /
• 2021

The study aimed to develop a high-power enzymatic electrode for a wearable fuel cell that generates electricity utilizing lactate present in a sweat as fuel. Anode was fabricated by immobilizing lactate oxidase (LOx) on flexible carbon paper. As the lactate concentration in the electrolyte solution increased, the amount of current generated by catalysis of lactate oxidase increased. The immobilized LOx generated 1.5-times greater oxidation current density in the presence of gold nanoparticles than carbon paper only. Bilirubin oxidase (BOD)-immobilized cathode generated a larger amount of reduction current in the electrolyte saturated with oxygen than purged with nitrogen. A fuel cell composed of two electrodes was fabricated and cell voltage was measured under different discharge current. At the discharge current density of 66.7 ㎂/cm², the cell voltage was 0.5±0.0 V leading to maximum cell power density of 33.8±2.5 ㎼/cm².