• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.86-93
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• 2021

In order to remove particulate matter, functional construction materials are developed. However, there is no evaluation method and infrastructure for particulate matter removal rate. Therefore, the purpose of this study was to build a particulate matter removal rate test chamber and to present a method for particulate matter removal rate. As a result, since construction materials have effectiveness in an environment where particulate matter is generated, the particulate matter injection step was proposed as a comparison target. The evaluation of the particulate removal rate was proposed by relative comparison of the slope values obtained by linear regression analysis for all concentration values measured in the particulate matter injection step. In linear regression method, all measured values can be evaluated, and the variability can be evaluated with the coefficient of determination (R-square), so that the reliability of the particulate matter removal rate can be secured.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.11-16
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• 2023

The technology of 3D reconstruction, primarily relying on point cloud data, is essential for digitizing objects or spaces. This paper aims to utilize reinforcement learning to achieve the acquisition of point clouds in a given environment. To accomplish this, a simulation environment is constructed using Unity, and reinforcement learning is implemented using the Unity package known as ML-Agents. The process of point cloud acquisition involves initially setting a goal and calculating a traversable path around the goal. The traversal path is segmented at regular intervals, with rewards assigned at each step. To prevent the agent from deviating from the path, rewards are increased. Additionally, rewards are granted each time the agent fixates on the goal during traversal, facilitating the learning of optimal points for point cloud acquisition at each traversal step. Experimental results demonstrate that despite the variability in traversal paths, the approach enables the acquisition of relatively accurate point clouds.

• Journal of Korea Water Resources Association
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• v.43 no.12
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• pp.1083-1091
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• 2010

Distributed hydrologic models typically require spatial estimates of precipitation interpolated from sparsely located observational points to the specific grid points. However, widely used estimation schemes fail to describe the realistic variability of daily precipitation field. We compare and contrast the performance of statistical methods for the spatial estimation of precipitation in two hydrologically different basins, and propose a two-step process for effective daily precipitation estimation. The methods assessed are: (1) Inverse Distance Weighted Average (IDW); (2) Multiple Linear Regression (MLR); (3) Climatological MLR; and (4) Locally Weighted Polynomial Regression (LWP). In the suggested simple two-step estimation process, precipitation occurrence is first generated via a logistic regression model before applying IDW scheme (one of the local scheme) to estimate the amount of precipitation separately on wet days. As the results, the suggested method shows the better performance of daily rainfall interpolation which has spatial differences compared with conventional methods. And this technique can be used for streamflow forecasting and downscaling of atmospheric circulation model effectively.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.62-68
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• 2014

Purpose: After I-131 therapy, SPECT/CT is useful in identifying location of thyroid remnants and metastasis of thyroid cancers. An excessive uptake of thyroid leads to a ringing artifact in the SPECT images. The aim of this study is to investigate and suggest a proper post filters to remove ringing artifact and produce better image quality. Materials and Methods: A low-cost, customized thyroid-mimicking phantom, consisting of an acrylic bottle and a hollow sphere was used for SPECT/CT Discovery (GE Healthcare, USA). It was filled with I-131 solution. The ratio of hollow sphere to background were varied as 50:1, 200:1, 1000:1 and 4000:1. Acquired images were reconstructed by OSEM (2 iterations, 10 subsets) with and without Evolution (resolution recovery correction, GE). Three different post-filters were applied; Butterworth (cut off: 0.38 to 0.58 with intervals of 0.05), Hanning (cut off: 0.8 to 1 with intervals of 0.05) and Gaussian (FWHM: 3 to 5 with intervals of 0.5) filters. Contrast, background variability, air area variability, and full width half maximum (FWHM) were compared. Results: Higher contrasts were obtained from the SPECT images with Evolution than without Evolution. In the case of images without Evolution, image distortion such as star artifact was generated. For all sphere-to-background ratio, the Butterworth filter showed better constrasts and FWHMs than other two filters, but the ringing artifact was still generated in all studies except 50:1 and it was decreased as cutoff value was increased. The ringing artifact didn't appear with Hanning and Gaussian filters at all studies, however constrats and FWHMs with Gaussian was worse than Hanning filter. For the images having ringing artifacts, the background variability and air area variability were increased. Conclusion: In this study, we suggested that it is desirable to use Hanning filter when the ringing artifact is generated and to use Butterworth filter when ringing artifact is not generated in I-131 SPECT.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.377-380
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• 1992

The value of the cell enzyme-linked immunosorbent assay as a possible replacement for the indirect immunofluorescence antibody test for the estimation of antibodies against BD virus was assessed in four animal models. The serum antibody response was measured by both assay systems;the variability of both tests was less than one diluent step, and correlation of the two tests was assessed using regression analysis. The study showed that the all four animal models gave satisfactory correlation of CELISA and IFA. There, CELISA is acceptable for use in mouse, rabbit, chicken and rat models.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.22-25
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• 2005

The 10 Year Implementation Plan for a Global Earth Observation System of Systems (GEOSS), which was endorsed at the Third Earth Observation Summit in Brussels in February, 2005, emphasizes the importance of data management facilities for diverse and large-volume Earth Observation data from inhomogeneous information sources. A three year research plan for addressing this key target of GEOSS has just approved as the first step by the Japanese government. The goals of this research are, (1) to develop a data management core system consisting of data integration and information fusion functions and interoperability and information service functions; (2) to establish data and information flows between data providers and users; (3) to promote application studies of data integration and information fusion, especially in the fields of weather forecasting, flood forecasting, agricultural management, and climate variability and changes. The research group involves leading scientists on information science and technology, who have been developing giant data archive servers, storage area networks, metadata models, ontology for the earth observations. They are closely cooperating with scientists on earth sciences, water resources management, and agriculture, and establishing an effective collaborative research framework.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.23-34
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• 1993

Although there are numerous studies that address the problem of optimal machine grouping and part family classification for cellular manufacturing, little research has been reported that studies the conditions where cellular manufacturing is appropriate. This paper, in order to evaluate and compare the job shop with the GT cellular shop, the performance of those shops were simulated by using SIMAN. We tested the effect of independent variables including changes of product demands, intercell flow level, group setup time, processing time variability, variety of material handling systems, and job properties (ratio of processing time and material handling time). And also performance measures (dependent variables), such as machine utilization, mean flow time, average waiting time, and throughput rate, are discussed. Job shop model and GT cellular shop written in SIMAN simulation language were used in this study. These systems have sixteen machines which are aggregated as five machine stations using the macro feature of SIMAN. The results of this research help to better understand the effect of production factors on the performance of cellular manufacturing systems and to identify some of the necessary conditions required to make these systems perform better than traditional job shops. Therefore, this research represents one more step towards the characterization of shops which may benefit from cellular manufacturing.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.449-454
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• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• Smart Structures and Systems
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• v.7 no.2
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• pp.133-152
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• 2011

System identification is a fundamental step towards the application of structural health monitoring and damage detection techniques. On this respect, the development of evolved identification strategies is a priority for obtaining reliable and repeatable baseline modal parameters of an undamaged structure to be adopted as references for future structural health assessments. The paper presents the identification of the modal parameters of the Guangzhou New Television Tower, China, using a data-driven stochastic subspace identification (SSI-data) approach complemented with an appropriate automatic mode selection strategy which proved to be successful in previous literature studies. This well-known approach is based on a clustering technique which is adopted to discriminate structural modes from spurious noise ones. The method is applied to the acceleration measurements made available within the task I of the ANCRiSST benchmark problem, which cover 24 hours of continuous monitoring of the structural response under ambient excitation. These records are then subdivided into a convenient number of data sets and the variability of modal parameter estimates with ambient temperature and mean wind velocity are pointed out. Both 10 minutes and 1 hour long records are considered for this purpose. A comparison with finite element model predictions is finally carried out, using the structural matrices provided within the benchmark, in order to check that all the structural modes contained in the considered frequency interval are effectively identified via SSI-data.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.186-191
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• 2016

A new UPLC-DAD method for simultaneous determination of p-coumaric acid and trans-cinnamic acid in propolis was developed using Halo-C18 column and step gradient elution of MeCN and $0.1%H_3PO_4$ in 8 min. The method was validated by specificity, linearity, limit of detection, limit of quantification, precision(intra- and inter-day variability) and recovery tests. The validated method was sufficiently applicable for quantitative analysis of propolis products as well as propolis collected from different regions in Korea. The established method is simple, appropriate and efficient, and can be used for quality assessment of Korean propolis.