• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.891-895
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• 2010

A dual-band (UHF: 470-862 MHz, L: 1452-1492 MHz) digital video broadcasting-handheld (DVB-H) antenna is presented. The proposed antenna is composed of a planar inverted F-shape antenna (PIFA) with an input impedance matching circuit. The matching circuit improves antenna performance in the broad UHF bands (470-862 MHz: 63%). The proposed antenna has omni-directional patterns and sufficient gain (Ave. peak gain is about 1.70 dBi over 470-862 MHz) for the PMP applications. The antenna is contact with a PMP case (${\varepsilon}_r=3.2$) which is used as a substrate for the size reduction and compact design.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.117-126
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• 2007

The purpose of this paper is to analyze the trends of technological development in the field of portable multimedia player (PMP) through patent information of major countries, and evaluate the technological Position of PMP. In the first place, we will carry out a quantitative analysis in terms of the annual trend of patent applications in the field of PMP, the technological position of PMP through portfolio analysis, the share of patents by applicant, the worldwide innovation leader of major countries, and the patent trend by IPC. Secondly, we will measure the technological level of PMP using indicators including cites per patent (CPP), science linkage (SL), and patent family size (PFS). Finally, we will evaluate the directions of research or technology development and the technological competitiveness of major countries. This evaluation could give us some useful policy implications on the strategy of R&D in PMP.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.846-849
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• 2009

본 논문에서는 듀얼 밴드(UHF: 470-862 MHz, L: 1452-1492 MHz) DVB-H 안테나를 제작하였다. 제안된 안테나는 입력 임피던스 매칭 회로를 이용한 평판형 역 F 안테나(PIFA)로 구성되었다. 급전점에 구성된 매칭 회로는 안테나의 광대역(UHF: 470-862 MHz: 63%) 동작특성을 만족시킨다. 제시된 안테나는 전방향적 방사특성을 가지며 상용 모바일(PMP)에 적용가능한 충분한 이득(최대이득: 1.70dBi)을 보인다. 또한 안테나는 유전율($\varepsilon_r$ = 3.2)인 PMP 케이스에 부착되어 상용 모바일용으로 소형화 되었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.865-871
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• 2010

A compact dual-band(IEEE 802.11b: 2.4~2.5 GHz, 11a: 5.15~5.825 GHz) 2-channel MIMO antenna for PMP applications is presented. The proposed antenna is composed of a planar inverted F-shape antenna(PIFA) operating at 2 GHz band and a loop antenna operating at 5 GHz band. The proposed antenna is orthogonally arranged at the edge of the ground plane for polarization and pattern diversities with excellent isolation characteristics. The two PIFA antennas operating 2 GHz have connecting line($\lambda_g$/4) face to the feed point for high isolation and low correlation at 2 GHz band. The two loop antennas connected each other in the bottom side to improve the isolation at 5 GHz band. The proposed antenna has a sufficient gain in WLAN service band and is compact sized for the portable media player (PMP) applications.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2007.11a
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• pp.123-123
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• 2007

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.209-218
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• 2008

The Unified Modeling Language becomes popular to specify, visualize, construct, and document software-intensive systems, especially in supporting the design phase of software engineering. Most of designs in UML have focused on firm designing of software system structure. Recently, some researches have raised additional demands in many emerging complex software systems, such as aspect-oriented design. In this paper, we work on the dynamic aspect of policy-driven architecture. We present a UML-based high-level modeling of policy-driven management which is applicable in various application domains. In order to manage a number of activities of applications, dynamics and flexibility should be supported with policies consistently on different resources in the same context. Thus, a methodology of meta-modeling to represent dynamic aspects of policy-driven architecture is studied. Based on our methodology, we could achieve meta-modeling to develop a number of policy-driven management applications.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.17-18
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• 2006

Flat Panel Displays (FPDs) have made a revolution in the display industry. TFT-LCD (Thin Film Transistor Liquid Crystal Display) has been the main player of FPD for last two decades. As the industry continuously develops the technology for better performance with lower cost is constantly demanded where several post LCD technologies are being developed. One of the prime candidates of post LCD technology is AMOLED (Active Matrix Organic Light Emitting Diode) that is considered to be an ideal FPD due to its extraordinary display performance and potentially low cost display structure. This technology has been accepted to small size display applications, such as cellular phone, PDA and PMP, etc. In this paper it is discussed that how this technology can be extended to large size display applications, such as TV. The technical issues and solutions of TFT backplane and color patterning of OLED materials are discussed and proposed

• Progress in Medical Physics
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• v.31 no.3
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• pp.35-53
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• 2020

The authors congratulate the cerebrations for the 30 years of the Korean Society of Medical Physics (http://www.ksmp.or.kr/). The paper is published to recognize the anniversary. Geon-Ho Jahng invited Professor Z. H. Cho to join to submit this manuscript because he has been one of the leaders in the field of magnetic resonance imaging (MRI) during the last 40 years. In this review, we describe the development and clinical histories of MRI internationally and domestically. We also discuss diffusion and perfusion MRI, molecular imaging using MRI and MR spectroscopy (MRS), and the hybrid systems, such as positron emission tomography-MRI (PET-MRI), MR-guided focused ultrasound surgery (MRgFUS), and MRI-guided linear accelerators (MRI-LINACs). In each part, we discuss the historical evolution of the developments, technical developments, and clinical applications.

• Progress in Medical Physics
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• v.32 no.1
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• pp.1-17
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• 2021

The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positron-emission-tomography-CT and single-photon-emission-computed-tomography-CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.

• Progress in Medical Physics
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• v.28 no.3
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• pp.122-128
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• 2017

Eclipse Scripting Application Programming Interface (ESAPI) was devised to enhance the efficiency in such treatment related workflows as contouring, treatment planning, plan quality measure, and data-mining by communicating with the treatment planning system (TPS). It is provided in the form of C# programming based toolbox, which could be modified to fit into the clinical applications. The Scripting program, however, does not offer all potential functionalities that the users intend to develop. The shortcomings can be overcome by combining the Scripting programming with user-executable program on Windows or Linux. The executed program has greater freedom in implementation, which could strengthen the ability and availability of the Scripting on the clinical applications. This work shows the use of the Scripting programming throughout the simple modification of the given toolbox. Besides, it presents the implementation of combining both Scripting and user-executed programming based on MATLAB, applied to automated dynamic MLC wedge and FIF treatment planning procedure for promoting the planning efficiency.