Comparison of Usage Cases in Nuclear Industry of Hand-held Gamma-ray Imagers

Manhee Jeong,Jihwan Boo,Seoryeong Park,Suyeon Hyeon 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.11

Development of a Monte Carlo Simulation Code (MCSDI) and Its Test Results for Optimal Design of a Digital Radiographic System Based on CMOS Image Sensor

ManHee Jeong,B.R. Park,B.S. Han,B.S. Lee,H.S. Cho,S. Kim 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.2

We have developed a Monte Carlo simulation code, the so-called Monte Carlo Simulation for Digital Imager (MCSDI), using the Visual C++ programming language for the optimal design of a digital radiographic system. The MCSDI code has emulated a variety of test conditions for X-ray energy distributions (bremsstrahlung and characteristic X-rays) and exposure levels, beam shapes (parallel or cone-shaped), and scintillator types and structures (Gd2O2S : Tb or CsI(Tl), and at or columnar), and a variety of test phantoms. In this paper, we describe the image characteristics of a digital radiographic system based on a CMOS image sensor using the MCSDI code in terms of the contrast-to-noise ratio (CNR), the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum eciency (DQE). This code is expected to be useful in designing the optimal components for a digital radiographic system with respect to the detector pixel size, the scintillator type and thickness, the tube voltage, the exposure level, and so on.

Microstrip Transmission-Line Electrodes for Position Sensitive Radiation Detection

Manhee Jeong,Hammig, Mark D. IEEE 2014 IEEE transactions on nuclear science Vol.61 No.6

<P>A serpentine transmission-line in a microstrip configuration is used to enable fine position sensing in semiconductor radiation detectors. Specifically demonstrated with silicon substrates coupled to standard charge-sensitive preamplifiers, a meandering electrode is used to enable lateral position sensing to within an approximately 1 cm length along the electrode. Configured in a rectilinear shape, the lateral resolution is therefore equivalent to the strip pitch, which we have made as small as 4 μm. The position-of-interaction is extracted using either timing or amplitude techniques, both enabled by the slow-wave propagation structure inherent to the standard metal-semiconductor-insulator configuration of the bounding electrodes, the analysis of which is summarized and compared experimentally.</P>

Reconsidering Japan’s Abenomics in Korea’s Economic Security

Manhee Lee(이만희) 21세기정치학회 2015 21세기 정치학회보 Vol.25 No.4

This paper explores the impact of Abenomics on Korea’s economic security. The Abenomics is considered as a manifestation of Abe’s nationalism. It aims to achieve his non-economic objective with economic significance therein. The Abenomics has a duty to satisfy its clients. For around 2 years, it fails to do so mostly due to a poor performance, which in turn forces the regime to reproduce more populist policies as a way to preserve the public support. The populism leads Abe to his nationalistic external behaviors. His successive obstinate statements on wartime legacies and territorial dispute manifest a nationalistic posture. As a way to satisfy his clients and to cheat his mismanagement, Abe would bolster more nationalistic trade and financial policies toward Korea. The beggar-thy-neighbor strategy heavily relying on more depreciated yen and reduction of direct investment in consequence increases Korea’s opportunity cost of troubles in economic relations and also endangers to dismantle interdependent nexus. As a way to ameliorate the opportunity cost, Korea should cultivate more markets overseas by proliferating bilateral and multilateral FTA networks like the TPP, while making more efforts to reshape friendly relations by adhering an importance to “intergovernmental need-driven pragmatism”. A well-coordinated economic relation could be geared to growing interdependence in other sectors such as security affairs.

Characteristics of a Planar-type Cd0.9Zn0.1Te Radiation Detector Grown by Using the Low-pressure Bridgman Method

Manhee Jeong,김한수,Young Soo Kim,Jang Ho Ha 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.8

An indium-doped (7 ppm) Cd0.9Zn0.1Te single crystal for use in room-temperature radiationdetectors has been grown using a low-pressure Bridgman (LPB) furnace at the Korea AtomicResearch Institute. The single crystal has a (111) orientation and a high resistivity of 1 × 1012 ·cm. In addition, the mobility-lifetime products of the electrons and hole are 4.2 × 10−4 cm2/Vand 5 × 10−5 cm2/V, respectively. These values are simply derived by using a Hecht and a neuralequation and 5 MeV alpha particles emitted from an 241Am alpha source. To characterize theCd0.9Zn0.1Te grown by using the LPB method, we fabricated planar detectors with volume of 10× 10 × 2.5 mm3 from a 2-inch-diameter Cd0.9Zn0.1Te ingot.

Design of an Intelligent System for Autonomous Groundwater Management

Manhee Lee 한국정보기술융합학회 2014 JoC Vol.5 No.1

Fluid-induced resonances in vibrational and Brownian dynamics of a shear oscillator

Manhee Lee,JongGeun Hwang,Bongsu Kim,안상민,Wonho Jhe 한국물리학회 2016 Current Applied Physics Vol.16 No.11

We generally describe vibrational and Brownian dynamics of a shear oscillator interacting with a confined Newtonian fluid. We show that the shear oscillator exhibits three characteristic dynamics in viscous, weak inertial, and strong inertial regimes, and the dynamics are controlled by two system parameters, effective confining height and oscillator-fluid coupling strength. While resonances of oscillators are usually deteriorated in fluids, we interestingly find the resonances arisen in originally overdamped oscillators, originated from hydrodynamic memory effects in strong inertial regime. The present theory could be exploited for improving designs and performances of shear oscillators in fluids, and reciprocally for investigating fluid properties by using shear oscillatory probes such as atomic force microscope in shear-mode.

Japan`s Reinterpretation of Its Right to Collective Self-Defense in the East Asian Power Transition

( Manhee Lee ) 국방대학교 안보문제연구소 2015 The Korean Journal of Security Affairs Vol.20 No.2

This paper explores why Japan advocates reinterpreting Article 9 of its constitution which defines its right to collective self-defense by adopting power transition theory as an analytical framework. The Senkaku Islands dispute compelled Japan to realize that China intended to alter the status quo. Japan found it urgent to counter China``s power. Against China``s successive provocative actions, Japan needed to reconsider its security posture and attach more importance to its close ties with the US. The reinterpretation was conceived not only as an effective countermeasure against China``s threats, but also as a policy change to satisfy American requests. Japan``s reinterpretation marks a few implications for Korea``s security relations with China and Japan. First, Korea should put more importance on the interconnected nexus of security and economy because the anti-status quo power would employ economic asymmetrical interdependence as an instrument to achieve its non-economic objectives. Second, in order to offset Korea``s vulnerabilities, multilateral regimes should be reconsidered as useful in economic and security terms. Lastly, naive liberalism and patchwork realism should be viewed with wariness.

일반논문 : 융복합 시대의 글쓰기 교육의 방향성 -창의적 문제 해결 능력 함양을 중심으로-

원만희 ( Manhee Won ) 성균관대학교 인문학연구원(성균관대학교 인문과학연구소) 2015 人文科學 Vol.0 No.59

이 시대는 대학에게 융복합 교육을 요구하고 있다. 융복합 교육은 개별화된 학문의 벽을 허물고 다양한 종류의 학문적 내용을 동시에 수용, 분석, 비판하고 새로운 결과물을 산출하는 능력의 함양을 요구한다. 이를 위해서는 학문을 가로지르는 융합적 사고 능력을 갖추는 것과 함께사고 결과물을 생생하고 정확하게 표현하는 도구를 활용하는 능력도 갖추어야 한다. 글쓰기는 이 점에서 융복합의 핵심적 도구라 할 수 있다. 글쓰기는 어떤 생각을 타인에게 전달하는 기능만 하는 것이 아니다. 말하기와는 달리 글쓰기는 그 과정에서 생각을 모으고, 정리할 뿐만 아니라 정리된 생각으로부터 새로운 지식을 형성하기도 한다. 여기서 필자는융복합적 사고, 즉 창의적이고 다면적인 사고가 글쓰기와 더불어 ‘효과적으로’ 시작되고 또 진행된다는 점을 강조하고 싶다. 바로 이 점이 융복합교육과 관련하여 글쓰기를 거론하는 진정한 이유이다. 이 글의 목적은 기본적으로 융복합 시대에 바람직한 글쓰기 교육의 방향성을 모색해 보는 것이다. 이를 위해 요즘 한창 회자되고 있는 ‘융복합’이 교육적으로 어떤 의미를 갖는지 먼저 살펴보았다. 그런 다음 융복합 교육을 위해서 글쓰기가 어떤 역할을 할 수 있는지 논의하고, 그 과정에서 글쓰기 교과목이 융복합 교육과 맺는 연관성, 즉 수렴적 창의성교육의 의미를 규명하고, 궁극적으로는 글쓰기와 융복합 교육의 효율적결합 방식으로서 ‘융복합형’ WAC 수업의 도입 필요성을 그 구체적 수업모형과 함께 제시하였다. The era of convergence and integration requires a person equipped with the capability of creative problem-solving. Therefore, it is hard to go against the tide of times that the goal of college education is changing to develop students` creative problem-solving capability. In this sense, writing education can and should reinforce student`s convergent creativity as a core capability of creative problem-solving. In order to develop writing education into an efficient method of achieving the proposed goal, students should be encouraged to use convergent and divergent thinking harmoniously to write better. Particularly, writing can be an efficient tool for developing this capability in major classes which are designed as a space for convergent and integrative study. In these classes, students are able to exercise creative problem-solving through writing, because writing is not only an activity for convergent and divergent thinking but also an activity for using various pieces of knowledge and information together. For example, the WAC (writing across the curriculum) program can be a good model for the combination of a convergent and an integrative class for writing. Therefore, it is important to seek for a new direction of writing education at college to educate creative and multi-aspect students in the era of convergence and integration.

A novel fabrication process for out-of-plane microneedle sheets of biocompatible polymer

Han, Manhee,Hyun, Dong-Hun,Park, Hyoun-Hyang,Lee, Seung S,Kim, Chang-Hyeon,Kim, ChangGyou IOP 2007 Journal of micromechanics and microengineering Vol.17 No.6

<P>This paper presents a novel process for fabricating out-of-plane microneedle sheets of biocompatible polymer using in-plane microneedles. This process comprises four steps: (1) fabrication of in-plane microneedles using inclined UV lithography and electroforming, (2) conversion of the in-plane microneedles to an out-of-plane microneedle array, (3) fabrication of a negative PDMS mold and (4) fabrication of out-of-plane microneedle sheets of biocompatible polymer by hot embossing. The in-plane microneedles are fabricated with a sharp tip for low insertion forces and are made long to ensure sufficient penetration depth. The in-plane microneedles are converted into an out-of-plane microneedle array to increase the needle density. The negative mold is fabricated for mass-production using a polymer molding technique. The final out-of-plane microneedle sheets are produced using polycarbonate for biocompatibility by employing the hot embossing process. The height of the fabricated needles ranges from 500 to 1500 ?m, and the distance between the needles is 500 to 2000 ?m. The radii of curvature are approximately 2 ?m, while the tip angles are in the range of 39–56?. Most of the geometrical characteristics of the out-of-plane microneedles can be freely controlled for real life applications such as drug delivery, cosmetic delivery and mesotherapy. Since it is also possible to mass-produce the microneedles, this novel process holds sufficient potential for applications in industrial fields.</P>