• Korean Journal of Computational Design and Engineering
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• v.10 no.1
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• pp.27-39
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• 2005

Implicit surfaces are geometric shapes which are defined by implicit functions and exist in three-dimensional space. Recently, implicit surfaces have received much attention in solid modeling applications because they are easy to represent the location of points and to use boolean operations. However, it is difficult to chart points on implicit surfaces for rendering. As efficient rendering method of implicit surfaces, the original Adaptively Sampled Distance Fields (ADFs) $method^{[1]}$ is to use sampled distance fields which subdivide the three dimensional space of implicit surfaces into many cells with high sampling rates in regions where the distance field contains fine detail and low sampling rates where the field varies smoothly. In this paper, in order to maintain the sharp features efficiently with small number of cells, an extended ADFs method is proposed, applying the Dual/Primal mesh optimization $method^{[2]}$ to the original ADFs method. The Dual/Primal mesh optimization method maintains sharp features, moving the vertices to tangent plane of implicit surfaces and reconstructing the vertices by applying a curvature-weighted factor. The proposed extended ADFs method is applied to several examples of implicit surfaces to evaluate the efficiency of the rendering performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2479-2485
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• 2013

In this paper, we present a design for solid-state radar SSPA with sequential bias. We apply to variable extension pulse generator to eliminate signal distortion which is caused by bias rising/falling delay of power amplifier. There is an optimum impedance matching circuit to have high efficiency of GaN-power device by measuring microwave characteristics through load-pull method. The designed SSPA is consisted of pre-amplifier, drive-amplifier and main-amplifier as a three stages to apply for X-Band solid-state radar. Thereby we made a 200W SSPA which has output pulse maximum power shows 53.67dBm and its average power is 52.85dBm. The optimum design of transceiver module for solid-state pulse compression radar which is presented in this dissertation, it can be available to miniaturize and to improve the radar performances through additional research for digital radar from now on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1555-1560
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• 2005

The presentation of query results is usually made with an external tool or a report generator but, because the methods of preparing and storing presentations have not been standardized, there are many difficulties for other applications to use query results. Thus, it is necessary for a multimedia data query language to define presentation in a standardized method. In this paper we designed extented SQL is based on SMIL 2.0, which support the proposed presentation model effectively. Furthermore this study proposed methods of using query results in various multimedia applications.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.2
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• pp.110-116
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• 2005

It is very important to reduce the computational processing time for the application of the vision system in real time such as inspection, the determination of object's dimension and welding etc, because the vision system model involves a lot of measurement data acquired by CCD camera. Also, a lot of computation time is required in estimating the parameters in the vision system model if the iterative batch estimation method such as Newton Raphson is used. Thus, the effective computation method such as the Extended Kalman Filtering(EKF) is required to solve the above problems. The EKF has much advantages in that it takes explicitly into account the measurement uncertainties, and is a simple and efficient recursive procedures. Thus, this study is to develop the EKF algorithm to compute the parameters in the vision system model in real time. This vision system model involves the six parameters to account for the cameras inner and outer parameters. Also the EKF is applied to estimate the object's dimension. Finally, practicality of the estimation scheme of the vision system based on the EKF is verified experimently by performing the estimation of object's dimension.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4234-4243
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• 2012

USN(Ubiquitous Sensor Network) application S/W has a complex characteristic that it controls various kind of sensor nodes organically based on the core modules of various target operating systems. Currently, various researches for efficient S/W development are being performed in USN application field. In order to increase S/W productivity, the method such as product line development approach to specify core common functions of applications according to the domain and develop applications with the core common functions and variant functions selected according to the workflow of applications is efficient. To apply this approach to the USN domain, characteristics of USN application S/W and product line development should be specified with one consistent view. However, it is difficult to efficiently specify the characteristics using general UML notations. In order to solve the problem, this paper proposes a method to effectively specify the characteristics of USN applications and product line development using UML profile which is the extension mechanism of UML. The proposed UML profile for produce line based USN application development enables developers to effectively develop product line based USN applications using existing UML and UML support tools without new design methods or tools which are specified for USN or product line development.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.1
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• pp.25-32
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• 2020

In the context-aware system, rule-based AI technology has been used in the abstraction process for getting context information. However, the rules are complicated by the diversification of user requirements for the service and also data usage is increased. Therefore, there are some technical limitations to maintain rule-based models and to process unstructured data. To overcome these limitations, many studies have applied machine learning techniques to Context-aware systems. In order to utilize this machine learning-based model in the context-aware system, a management process of periodically injecting training data is required. In the previous study on the machine learning based context awareness system, a series of management processes such as the generation and provision of learning data for operating several machine learning models were considered, but the method was limited to the applied system. In this paper, we propose a training data generating method of a machine learning model to extend the machine learning based context-aware system. The proposed method define the training data generating model that can reflect the requirements of the machine learning models and generate the training data for each machine learning model. In the experiment, the training data generating model is defined based on the training data generating schema of the cardiac status analysis model for older in health status notification service, and the training data is generated by applying the model defined in the real environment of the software. In addition, it shows the process of comparing the accuracy by learning the training data generated in the machine learning model, and applied to verify the validity of the generated learning data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.341-350
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• 2007

In this paper, the derivation of protection ratio is newly proposed for the detailed planning of frequency coordination in microwave relay networks, and computed results for protection ratio of co-channel and adjacent channel are illustrated over the actual system and its frequency. It is shown that the suggested method based upon availability prediction can be expressed in terms of composite fade margin, interference-to-noise ratio(I/N), net filter discrimination, and system parameters. According to results, for 6.7 GHz, 60 km, 64-QAM, and I/N= -6 dB at BER $10^{-6}$, composite fade margin and co-channel protection ratio provide 25.5 and 50.7 dB, respectively. Also, net filter discrimination and adjacent channel protection ratio are obtained as 26.3 and 24.4 dB, respectively, at the first adjacent channel of 40 MHz. The proposed method provides some merits in computing protection ratio for microwave relay networks in view of an easy extension and practical applications considering more detailed and various system parameters.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.90-96
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• 2009

The aim of the research is that disease database of the glycosuria and heart's blood is designed to manage the condition of the glycosuria and heart's blood patients periodically and continuously. Also we integrate patient database of existing OCS, PACS, EMR, ERP etc. and support optimal service timely that the patients want through intelligent integrated interface environment. For this, we will develop customized medical information convergence system. We construct intelligent database for disease of the glycosuria and heart's blood. And we support data integration environment for connection with existing systems - OCS, EMR, PACS etc. Also, in consideration of QoS, reliability, and expandability of customized medical information convergence system, we will design H/W, S/W, and data compatibility method.

• The Korean Journal of Pharmacology
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• v.11 no.1 s.17
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• pp.33-38
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• 1975

The clinical efficacy of Ethaverine, a peripheral vasodilator, was studied according to a double-blind, non-cross over method in 29 diabetic patients with peripheral arterial diseases. The clinical improvement was assessed from the history of patients including the incidence and frequency of intermitten claudication. Ethaverine, after 4 weeks of therapy, was not effective in improving clinical symptoms compared to placebo. Ethaverine, however, was an efective vasodilator than placebo. The quality of vasodilation induced by Ethaverine, was similar to that of alcohol. A new clinical method of studying peripheral vasodilator was presented. The clinical symptoms of peripheral vascular arterial disease in the lower extrimities include reduced intensity of palpable pulses, coldness, and discoloration of the skin. Intermittent claudication may be present. Pathologic changes in vessel architecture precede the symptoms, and recognition of impending vascular insufficiency is a determining factor in selecting vasodilating therapy or surgical management. Also, post-operative patients who have chronic peripheral vascular arterial disease may be candidates for subsequent vasodilating therapy. Peripheral vasodilators, according to the series of reports, may be indicated in vasospastic peripheral vascular condition rather than an occlusive vascular disease and the vessel responds best when a relatively large vascular beds are involved rather than a small, capillary beds. Recently, the clinical efficacy of peripheral vasodilators have been challanged by many clinical investigators and clinicians. In this study, we have re-evaluated the efficacy of Ethaverine HCl as peripheral vasodilator in patients with vasospastic peripheral arterial disease. Ethaverine is claimed to be two to four times as potent a spasmolytic agent as papaverine in a variety of laboratory and clinical work.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.43-51
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• 2010

This paper proposes an analysis of voltage delay and compensation for current control in H-Bridge Multi-Level (HBML) inverters for a medium voltage motor drive with vector control. It is shown that the expansion and modularization capability of the HBML inverter is improved in case of using Phase-Shifted Pulse Width Modulation (PSPWM) since individual inverter modules operate more independently. But, the PSPWM of HBML has a phase difference between reference voltage and real voltage, which can cause instability in the current regulator at high speed where the ratio of the sampling frequency to the output frequency is insufficient. This instability of the current regulator is removed by adding a proposed method which compensate a phase difference between reference voltage and real voltage. The proposed method is suitable for HBML inverter controlled by PSPWM with low switching frequency and high speed motor drive. The validity of the proposed method is verified experimentally on 6,600[V] 1,400[kW] induction motor fed by an 13-level HBML inverter.