• Journal of radiological science and technology
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• v.35 no.4
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• pp.309-314
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• 2012

Nowadays, digital Radiography (DR) systems are widely used in clinical sites and substitute the analog-film x-ray imaging systems. The resolution of DR images depends on several factors such as characteristic contrast and motion of the object, the focal spot size and the quality of x-ray beam, x-ray scattering, the performance of the DR detector (x-ray conversion efficiency, the intrinsic resolution). The DR detector is composed of an x-ray capturing element, a coupling element and a collecting element, which systematically affect the system resolution. Generally speaking, the resolution of a medical imaging system is the discrimination ability of anatomical structures. Modulation transfer function (MTF) is widely used for the quantification of the resolution performance for an imaging system. MTF is defined as the frequency response of the imaging system to the input of a point spread function and can be obtained by doing Fourier transform of a line spread function, which is extracted from a test image. In clinic, radiologic technologists, who are in charge of system maintenance and quality control, have to evaluate or make routine check on their imaging system. However, it is not an easy task for the radiologic technologists to measure MTF accurately due to lack of their engineering and mathematical backgrounds. The objective of this study is to develop and provide for radiologic technologists a medical system imaging evaluation tool, so that they can measure and quantify system performance easily.

• Journal of the Korean Applied Science and Technology
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• v.17 no.4
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• pp.273-278
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• 2000

Cellulose tosylate(CT) was prepared by reaction of cellulose with p- toluenesulfonylchloride in DMAc/LiCl homogeneous system. In order to study a reversible photoisomerization of disperse red 1(DR-1) attached on natural polymer, cellulose tosylate containing DR-1(DR-1/CT adduct) was prepared at $110^{\circ}C$ in DMAc, and the changes of UV/Vis spectra of its solutions and thick film were investigated by alternate irradiation technique. Form the UV/Vis spectra of DR-1/CT adduct dissolved in cosolvents, such as DMAc, DMAc/THF, DMAc/benzene, and DMAc/chloroform and irradiated with 360 nm and 450 nm ligths, we found out changes of UV/Vis spectra were reversible in all solvents systems and we found out changes of UV/Vis spectra were reversible at thick film, also.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.33.4-33
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• 2002

Recently, number of navigation system using GPS and other complementary sensor has been developed to offer high-position accuracy. In this paper, we developed navigation system for mobile robot integrating GPS and DR sensor information provided by fiber optic gyroscopes and encoder information. In the case of short-term applications, integrating this encoder and gyroscope through Kalman filter reliable positioning can be obtained. And for the long-term applications we developed GPS/DR Integration algorithm using Kalman filter

• 한국IT서비스학회:학술대회논문집
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• 2002.11a
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• pp.459-466
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• 2002

위기관리의 목적은 각종 재해 ${\cdot}$ 재난으로 인한 비상사태 발생시 기업의 업무를 지속하고, 신속하게 피해 업무를 복구하는데 있다. 이러한 위기관리의 목적 자체는 언제 어디서나 변함이 없지만, 그 구성 내용과 운영 방안은 시대와 장소에 따라 업무 환경에 알맞도록 적절하게 구성되어야 한다. 따라서 본 논문에서는 한국 기업 환경에 적합한 Business Continuity를 위한 위기관리시스템 개발 모델을 DR. PEAS(Disaster Recovery Plan & Execution Automation System)의 사례를 통하여 제시하고자 한다.

• Korean Journal of Head & Neck Oncology
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• v.13 no.1
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• pp.16-23
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• 1997

Although normal thyroid epithelial cells do not constitutively express HLA-DR antigen, their expression in wide spread within thyroid glands obtained from the human with autoimmune thyroid disease and with many neoplastic thyroids. We have, therefore, studied immunohistochemically with regard to the expression of HLA-DR antigen of thyroidectomy specimens from 50 patients of various thyroid diseases with use of paraffin-embedded tissue. One or two sections from each case were stained with commercially available mouse monoclonal antibody for class II HLA-DR antigen(HLA-DR/Alpha, DAKO) and examined by semiquantitative counting system for thyrocytes, neoplastic thyrocytes and other cells expressing HLA-DR antigen. All patients with lymphocytic thyroiditis(2/2) and diffuse hyperplasia(Graves' disease)(5/5), most patients with Hashimoto's disease(9/ll) expressed HLA-DR antigens in thyrocyte with abundant HLA-DR expressing lymphocytic infiltrates with lymph follicle formation in its vicinity or adjacent to the lesion. Most patients with papillary carcinoma(9/1l) had HLA-DR antigen detected in malignant thyrocytes ; while follicular carcinoma(0/3) and follicular adenoma(0/5) did not have detactable HLA-DR immunoreactivity. Adenomatous goiter(3/7) had HLA-DR antigen detected focally in lesser than half cases. Conversely, in four papillary carcinomas and three adenomatous goiters, HLA-DR expression of thyrocytes was found in the absence of HLA-DR expressing lymphoid infiltrates. In such cases therefore other factors more than thyroid autoimmunity must be causative for HLA-DR immunoreactivity. The results of this study indicate as follows. 1) The expression of HLA-DR on thyrocytes involved in autoimmune reactions appeared to be secondary to cytokine release from associated lymphocytic infiltrates. 2) Thyrocytes in thyroid lesions with equal degrees of lymphocytic infiltration without HLA­DR expression exhibited no HLA-DR immunoreactivity. 3) In neoplastic thyrocytes, most papillary carcinoma(9/11) exhibited detactable HLA-DR expression, while follicular carcinoma/adenoma(0/3/0/5) exhibited no detactable HLA-DR immunoreactivity which suggest the existence of divergent mechanisms inducing and modulating HLA-DR expression of different types of neoplastic thyrocytes.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.64.5-64
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• 2002

This paper concerns a new digital redesign (DR) technique for an observer-based output-feedback control (OBOFC) system. The term DR involves converting an analog controller into an equivalent digital one in the sense of state-matching. The considered DR problem is formulated as convex minimization problems of the norm distances between linear operators to be matched. The stability condition is easily embedded and the separation principle on the DR of the OBOFC is explicitly shown. A numerical example is included for visualizing the feasibility of the proposed technique.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.149-150
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• 2007

By adding Gyro sensor to support the steering wheel angle sensor, an improved functional DR solution is proposed in this paper The proposed angle data algorism is developed based on the steering wheel with Gyro sensor for DR. The Gyro sensor support the error of steering wheel sensor to improve the angle data for the DR algorism.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.4
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• pp.288-294
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• 2014

Understanding a ship's present position has been one of the most important tasks during a ship's voyage, in both ancient and modern times. Particularly, a ship's dead reckoning (DR) has been used for predicting traffic situations and collision avoidance actions. However, the current system that uses the traditional method of calculating DR employs the received position and speed data only. Therefore, it is not applicable for predicting navigation within the harbor limits, owing to the frequent changes in the ship's course and speed in this region. In this study, planned routes were applied for improving the reliability of the proposed system and predicting the traffic patterns in advance. The proposed method of determining the dead reckoning position (DRP) uses not only the ships' received data but also the navigational patterns and tracking data in harbor limits. The Mercator sailing formulas were used for calculating the ships' DRPs and planned routes. The data on the traffic patterns were collected from the automatic identification system and analyzed using MATLAB. Two randomly chosen ships were analyzed for simulating their tracks and comparing the DR method during the timeframes of the ships' movement. The proposed method of calculating DR, combined with the information on planned routes and DRPs, is expected to contribute towards improving the decision-making abilities of operators.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.2
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• pp.223-230
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• 2004

In this paper, we will introduce a control strategy based on the permanent magnet linear synchronous motor (PMLSM) container transfer system using soft-computing algorithm. Linear motor-based container transport system (LMCTS) is horizontal transfer system for the yard automation, which has been proposed to take the place of automated guided vehicle in the maritime container terminal. LMCTS is considered as that the system is changed its model suddenly and variously by loading and unloading container. The proposed control system is consisted of two DR-FNNs that act the role of controller and system emulator. Consequently, the system had the predictable structure and an ability to adapt for a huge variation of rolling friction, detent force, and sudden changes of its weight by loading and unloading.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.389-395
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• 2007

The Film X-ray and the CCD method of current medical image system have the disadvantages such as required large place and diagnosis time. In this paper, we implement an effective medical image system using TXT-DXD method's digital X-ray detector(DR1000C). The implemented medical image system has advantages of placing efficiency and short diagnosis time. In order to make the image out of the system more effective, we develop an LCD(Liquid Crystal Display) control driver, having the resolution of 1900*1200. And we propose an enhancement unsharp masking method to update image enhancement of DR1000C medical image system, and compare it with the current methods.