• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.785-791
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• 2020

The radiance measured from satellite has noise due to atmospheric effect. Atmospheric correction is the process of calculating surface reflectance by removing atmospheric effect and surface reflectance is calculated by the Radiative Transfer Model (RTM)-based Look-Up Table (LUT). In general, studies using a LUT make LUT for each channel with the same atmospheric and geometric conditions. However, atmospheric effect of atmospheric factors do not react sensitively in the same channel. In this study, the LUT for each channel of Korea Multi-Purpose SATellite (KOMPSAT)-3/3A was made under the same atmospheric·geometric conditions. And, the accuracy of the LUT was verified by using the simulated Top of Atmosphere radiation and surface reflectance in the RTM. As a result, the relative error of the surface reflectance in the blue channel that sensitive to the aerosol optical depth was 81.14% at the maximum, and 42.67% in the NIR (Near Infrared) channel.

• The KIPS Transactions:PartB
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• v.14B no.7
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• pp.493-502
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• 2007

An on-line registration technique is presented to register multi-view range images for the 3D reconstruction of real objects. Using a range camera, we first acquire range images and photometric images continuously. In the range images, we divide object and background regions using a predefined threshold value. For the coarse registration of the range images, the centroid of the images are used. After refining the registration of range images using a projection-based technique, we use a modified KLT(Kanade-Lucas-Tomasi) tracker to match photometric features in the object images. Using the modified KLT tracker, we can track image features fast and accurately. If a range image fails to register, we acquire new range images and try to register them continuously until the registration process resumes. After enough range images are registered, they are integrated into a 3D model in offline step. Experimental results and error analysis show that the proposed method can be used to reconstruct 3D model very fast and accurately.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.202-208
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• 2012

Fetal heart rate monitoring is important information to assess fetal well-being. Non-invasive fetal ECG (electrocardiography) can be derived from maternal abdominal signal. And various promising signal processing methods have been introduced to extract fetal ECG from mother's composite abdominal signal. However, non-invasive fetal ECG monitoring still has not been widely used in clinical practice due to insufficient reliable measurement and difficulty of signal processing. In application of signal processing method to extract fetal ECG, it might be lower signal to noise ratio due to time varying white Gaussian noise. In this paper, time varying Kalman smoother is proposed to remove white noise in fetal ECG and its feasibility is confirmed. Wiener process was set as Kalman system model and covariance matrix was modified according to white Gaussian noise level. Modified error covariance matrix changed Kalman gain and degree of smoothness. Optimal covariance matrix according to various amplitude in Gaussian white noise was extracted by 5 channel fetal ECG model, and feasibility of proposed method could be confirmed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.305-317
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• 2003

Underwater shape and hook depth in tuna longline gear are important factors to decide fishing performance. It also should be considered that management and analysis of hooked rate data from hooked fish species and sizes, and each fishing would be used as a reference data in the future fishing. In this research, after analyzing underwater shape of tuna longline gear by current direction and speed using simulation, experiments were executed in flume tank to verify accuracy of the analysis. Also using the depth of each hook from the simulation, a database system was setup to process the data of bait and hooked fish species. The results were as follows；1. When the attack angle and the shortening rate are fixed, a decrease of the hook depth is proportion to an increase of current speed. 2. When the shortening rate and current speed are fixed, a decrease of hook depth is proportion to an increase of attack angle. 3. When the attack angle and velocity of flow are fixed, a decrease of hook depth is proportion to an increase of shortening rate 4. As a result of comparison between the underwater shape by simulation and that by model gear, the result of the simulation was very close to that of model gear within $$ {\pm}3%$$ 3% error range. 5. In this research, hooked rate database system using hook depth of simulation can analyze the species and size of fish by the parameter; bait. hook depth, so It could be helpful to manage and analyze the hooked data on the field.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.532-538
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• 2020

In this study, emulsification process were conducted to manufacture the natural sunscreen from raw materials such as shea butter, olive emulsifier wax, and green tea extract. The emulsification was optimized by using the central composite design model-response surface methodology (CCD-RSM) where the response values were established as the mean droplet size (MDS) and emulsion stability index (ESI) after 7 days in addition to UV absorbance at 300nm. The amount of emulsifier and additives and emulsification time were established as operating variables and the optimal conditions of sunscreen emulsification were accepted as 3.70, 2.47 wt.%, and 15.42 min, respectively according to the result of CCD-RSM. On the other hand, the response values were estimated as 1173.80 nm and 99.56% for MDS and ESI, respectively, after 7 days, in addition to UV absorbance at 300 nm (2.47). The average error from actual experiments was a low level as about 3.0 ± 1.5%, which is mainly due to the fact that the optimization using CCD-RSM applied in this study was in the relatively high significant level.

• Korean Journal of Construction Engineering and Management
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• v.11 no.4
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• pp.22-31
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• 2010

Because the estimated cost at early stage has great influence on decisions of project owner, the importance of early cost estimation is increasing. However, it depends on experience and knowledge of the estimator mainly due to shortage of information. Those tendency developed into case-based reasoning(CBR) method which solves new problems by adapting previous solution to similar past problems. The performance of CBR model is affected by attribute weight, so that its accurate determination is necessary. Previous research utilizes mathematical method or subjective judgement of estimator. In order to improve the problem of previous research, this suggests CBR schematic cost estimation method using genetic algorithm to determine attribute weight. The cost model employs nearest neighbor retrieval for selecting past case. And it estimates the cost of new cases based on cost information of extracted cases. As the result of validation for 17 testing cases, 3.57% of error rate is calculated. This rate is superior to accuracy rate proposed by AACE and the method to determine attribute weight using multiple regression analysis and feature counting. The CBR cost estimation method improve the accuracy by introducing genetic algorithm for attribute weight. Moreover, this makes user understand the problem-solving process easier than other artificial intelligence method, and find solution within short time through case retrieval algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.455-458
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• 2013

The conventional design of the information system architecture based on the personal experience of information systems has been acted as a limit in progress utilizing appropriate resource allocation and performance improvements. Architecture design depending on personal experience makes differences in variance of a designer's experience, intellectual level in related tasks and surroundings, and architecture quality according to individual's propensity. After all these problems cause a waste of expensive hardware resources. At working place, post-monitoring tools are diversely developed and are running to find the bottleneck and the process problems in the information operation. However, there are no simulation tools or models that are used for expecting and counteracting the problems at early period of designing architecture. To solve these problems we will first develop a simulation model for designing information system architecture in a pilot form, and will verify validity. If an error rate is found in the permissible range, then it can be said that the simulation reflects the characteristic of information system architecture. After the model is developed in a level that can be used in various ways, more accurate performance computation will be able to do, getting out of the old way relying on calculations, and prevent the existence of idle resources and expense waste that comes from the wrong design of architecture.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1069-1077
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• 2008

The railway abrasion measurement system have to satisfy two conditions to increase the measurement accuracy as follows. The laser region which is projected on the rail have to be extracted without the geometrical distortion. The mapping of the acquired laser region data on the rail profile have to be processed exactly. But, the conventional railway abrasion measurement system is deeply effected by the foreign substance( dust, rainwater, and so on ) on the railway or the sensitive response characteristic of the laser to the external measurement circumstance, and then the measurement errors arise from above factors. When the laser region is projected on the rail extracts from the acquired image, the interference of the light with the same frequency as the laser system occurs the serious problems. In the process of the mapping between the railway profile and the extracted laser region, the measurement accuracy is very highly effected by the geometrical distortion and the abnormal variation. In this Paper, we propose the novel method to increase the accuracy of the railway abrasion measurement dramatically. we designed and manufactured the high precision and fast image processing board with DSP Core and FPGA to measure the railway abrasion. The image processing board has the capability that the image of 1024X1280 from camera can be processed with the speed of 480 frame/sec. And, we apply the image processing algorithm base on the wavelet to extract the laser region is projected on the rail exactly. Finally, we developed high precision railway abrasion measurement system with the error range less than +/-0.5mm by which 2D image data is covered 3D data and mapped on the rail profile using the camera model and the perspective transform.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.663-669
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• 2018

The process of extracting active ingredients from wheat sprout using ultrasound assisted method was optimized with a central composite design model. The response value of the central composite design model established the extraction yield and the total flavonoids content, main effects and interactive effects were analyzed depending on independent variables such as the extraction time, volume ratio of ethanol to ultrapure water, and ultrasonic irradiation power. The volume ratio of ethanol to ultrapure water and ultrasonic irradiation power were relatively large for the extraction yield and the extraction time was most significantly affected the total flavonoids, Considering both the extraction yield and total flavonoids content, the optimal extraction conditions were as follows: the extraction time of 17.00 min, volume ratio of ethanol to ultrapure water of 50.25 vol%, ultrasonic irradiation power of 551.70 W. In this case, the extraction yield and total flavonoids content were 28.43 wt% and $29.99{\mu}g\;QE/mL\;dw$, respectively. The actual experimental extraction yield and total flavonoids content under this condition were 8.73 wt% and $29.65{\mu}g\;QE/mL\;dw$, respectively with respective error rates of 1.05 and 1.13%.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.408-414
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• 2019

In this study, an antioxidant was extracted from dandelion leaves using traditional hot water and ultrasonic extraction methods. In order to optimize the extraction yield and total flavonoid, an antioxidant, Box-Behnken design (BBD) model among response surface analysis methods was used. In the case of hot water extraction, the extraction temperature and time as well as the ratio of alcohol/ultrapure water were set as variables, and for the ultrasonic extraction, the ultrasonic survey century and irradiation time and the ratio of alcohol/ultrapure water were variables. Optimum extraction conditions in the hot water extraction method were the extraction temperature and time of $45.76^{\circ}C$ and 1.75 h and the ratio of alcohol/ultrapure water of 41.92 vol.%. While for the ultrasonic extraction method the survey century of 512.63 W, the ratio of alcohol/ultrapure water of 56.97 vol.% and the extraction time of 20.79 min were optimum conditions. Expected reaction yield and flavonoid content values under the optimized condition were calculated as 22.09 wt.% and 28.98 mg QE/mL dw, respectively. In addition, the error value of less than 3% was obtained validating our optimization process.