• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.173.2-173.2
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• 2016

A two-step oxidation method was applied on Al6061 to debate the growth mechanism of plasma electrolytic oxidation (PEO) coating. The specimens were first oxidized in the primary electrolyte solution {$Na_3PO_4$ (8g/l), NaOH (2g/l), consequently, the specimens were transferred into a different electrolyte {$K_2ZrF_6$ (8g/l), NaOH (2g/l), $Na_2SiF_6$ (0.5g/l)} for further oxidation. The processes was conducted for various processing times. It was found the second step electrolyte component were reached to inner layers, in contrast to the primary step components which were thrustle to the outer layer. The presence of the secondary component in the inner layers were significantly varied with processing time which suggest the change in growth properties with processing time. further more the inside growth of the secondary component confirmed the increasing trend in the downward growth of the coating layer. The corrosion and hardness properties of the coatings were found highly improved with change in growth features with increasing the processing time.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.14-17
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• 2016

This paper describes the implementation of automatic number-braille converter based on image processing for the blind people. The algorithm is consists of four main steps. First step is binary image conversion of the input image obtained by the camera. the second step is segmentation operation by means of dilation and labelling of the character. Next step is calculation of cross-correlation between segmented text image and pre-defined text-pattern image. The final step is generation of brail output which is relevant to input image. The computer simulation result was showing 91.8% correct conversion rate for arabian numbers which is printed in A4-sheet and practical possibility was also confirmed by using implemented automatic number-braille converter based on DSP image processing board.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.832-844
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• 2020

The degree of dispersion of a random variable can be described by the variance, which reflects the distance of the random variable from its mean. However, the time complexity of the traditional variance calculation algorithm is O(n), which results from full calculation of all samples. When the number of samples increases or on the occasion of high speed signal processing, algorithms with O(n) time complexity will cost huge amount of time and that may results in performance degradation of the whole system. A novel multi-step recursive algorithm for variance calculation of the time-varying data series with O(1) time complexity (constant time) is proposed in this paper. Numerical simulation and experiments of the algorithm is presented and the results demonstrate that the proposed multi-step recursive algorithm can effectively decrease computing time and hence significantly improve the variance calculation efficiency for time-varying data, which demonstrates the potential value for time-consumption data analysis or high speed signal processing.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.227-230
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• 2000

건설 도면정보의 공유 및 교환은 건설 CALS/EC(Continuous Acquisition & Lifecycle Support /Electronic commerce) 환경의 필수적인 요소이다. 그러나 CAD 시스템의 버전변화와 별도의 한글처리로 인하여 도면정보의 관리 렌 활용에 많은 문제점이 발생하고, 상이한 CAD 시스템간의 파일 교환이 제대로 이루어지지 못하는 등 도면정보 교환을 위한 정보모델의 구축이 절실히 요구되고 있다. 이러한 환경에서 STEP(Standard for the Exchange of Product model data)은 건설 도면정보의 교환 및 공유를 위한 정보모델을 구축함에 있어서 그 활용 가능성이 높다. 본 연구에서는 STEP을 이용하여 건설분야에서 활용 가능한 2차원 도면정보 모델을 개발하고자 한다. 이를 위하여 STEP내의 AP 202를 기반으로, AP 214와 독일의 2차원 도면정보 표준화 프로젝트인 STEP-CDS를 참조하도록 한다. 그리고 실제 개발된 도면정보모델이 기존 CAD 도면 데이터를 제대로 표현할 수 있는지 검증하기 위하여 상용 CAD시스템인 AutoCAD Rl4의 DXF 데이터를 개발된 정보모델로 변환하여 그 결과를 검토하고자 한다. 세부적으로는 DXF 데이터의 도면정보모델로의 변환을 위하여 DXF 구조의 STEP 스키마를 정의한다. 이때 이 스키마와 도면정보모델의 스키마간의 매핑을 위하여 STEP내의 EXPRESS-X를 이용하기로 한다. 또한 도면정보 모델의 데이터의 뷰잉과 브라우징을 위하여 도면정보 뷰어를 개발한다.

• Journal of Korea Water Resources Association
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• v.51 no.11
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• pp.1031-1041
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• 2018

ANFIS-based methodology for improving GloSea5 ensemble weather forecast is developed and evaluated in this study. The proposed method consists of two steps: pre & post processing. For ensemble prediction of GloSea5, weights are assigned to the ensemble members based on Optimal Weighting Method (OWM) in the pre-processing. Then, the bias of the results of pre-processed is corrected based on Model Output Statistics (MOS) method in the post-processing. The watershed of the Chungju multi-purpose dam in South Korea is selected as a study area. The results of evaluation indicated that the pre-processing step (CASE1), the post-processing step (CASE2), pre & post processing step (CASE3) results were significantly improved than the original GloSea5 bias correction (BC_GS5). Correction performance is better the order of CASE3, CASE1, CASE2. Also, the accuracy of pre-processing was improved during the season with high variability of precipitation. The post-processing step reduced the error that could not be smoothed by pre-processing step. It could be concluded that this methodology improved the ability of GloSea5 ensemble weather forecast by using ANFIS, especially, for the summer season with high variability of precipitation when applied both pre- and post-processing steps.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.445-453
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• 2012

This study examined microbial contamination during seasoned and dried squid Dosidicus gigas processing, including the apparatus, machines, and employee's gloves at each step in processing at two companies. The numbers of bacteria floating in air in each processing area were also examined. The numbers of Staphylococcus aureus (3.6-6.0 log CFU/g) and Escherichia coli (1.3-1.4 log MPN/100 g) in domestic and imported daruma (a semi-processed product of seasoned and dried squid) at companies A and B exceeded the regulatory limits of the Food Sanitary Law of Korea (S. aureus, ${\leq}2.0$ log CFU/g; E. coli, negative). S. aureus in both daruma was reduced to below the detection limit or 3.6 log CFU/g after the roasting step, but increased again to 3.3 and 5.5 log CFU/g after the mechanical tearing step at companies A and B, respectively. E. coli showed similar tendencies at both companies. The surfaces of the apparatus, machines, and employee's gloves that contacted daruma were also contaminated with S. aureus (1.0-5.5 log CFU/$m^2$) and E. coli (negative-to 3.5 log MPN/$m^2$). The numbers of bacteria floating in air were high (1.7-5.1 log CFU/$m^3$) at both companies. These results suggest that sanitation standard operating procedures (SSOP) must be developed to control of microbial cintamination in seasoned and dried squid.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.73-76
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• 2000

We investigate the stepwise parallel processing of the serial search which can success the co]1 search at low Ec/Io. The single path Rayleigh fading channel which is worst-case channel model is considered. The typical 3-step cell search is used. The probabilities of detection, miss and false alarm for each step are used in closed forms based on the statistics of CDMA noncoherent demodulator output. The optimal power allocation to each channel and The optimal number of post-detection integrations for each step is obtained. Also, the cumulative probability distribution of the average eel] search time for serial search methods are compared.

• 연구논문집
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• s.23
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• pp.45-56
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• 1993

In order to acquire more comprehensive understanding of textile composites, the processing-microstructure-performance relationships for a variety of material systems, reinforcing schemes and processing technologies should be established. In this paper, emphasis is placed on the integrated analysis of three-dimensional (3-D) 2-step braided composites. The analysis includes the geometric model of unit cells, identification of key process parameters and processing windows due to limiting geometries of yarn jamming, and prediction of elastic constants of the composite. The coordinate transformation and averaging of stiffness and compliance constants are utilized in the prediction of elastic constants. Since there are several types of unit cells in the thickness and width directions of the composites, characterization of mechanical properties is based upon the macro-cell, which occupies the entire cross-section and the unit pitch length of the sample. The performance map demonstrates that a wide range of elastic properties can be achieved by varying the geometric and process parameters.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.1
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• pp.9-14
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• 2015

Outlier detection and removal is a crucial step needed for various image processing applications such as image registration. Random Sample Consensus (RANSAC) is known to be the best algorithm so far for the outlier detection and removal. However RANSAC requires a cosiderable computation time. To drastically reduce the computation time while preserving the comparable quality, a outlier detection and removal method based on modified K-means is proposed. The original K-means was conducted first for matching point pairs and then cluster merging and member exclusion step are performed in the modification step. We applied the methods to various images with highly repetitive patterns under several geometric distortions and obtained successful results. We compared the proposed method with RANSAC and showed that the proposed method runs 3~10 times faster than RANSAC.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.374-381
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• 2023

In a previous study, 'response surface methodology (RSM) using a fullest balanced model' was proposed to improve the optimization of food processing when a standard second-order model has a significant lack of fit. However, that methodology can be used when each factor of the experimental design has five levels. In response surface experiments for optimization, not only five-level designs, but also three-level designs are used. Therefore, the present study aimed to improve the optimization of food processing when the experimental factors have three levels through a new approach to RSM. This approach employs three-step modeling based on a second-order model, a balanced higher-order model, and a balanced highest-order model. The dataset from the experimental data in a three-level, two-factor central composite design in a previous research was used to illustrate three-step modeling and the subsequent optimization. The proposed approach to RSM predicted improved results of optimization, which are different from the predicted optimization results in the previous research.