• Electrical & Electronic Materials
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• v.15 no.12
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• pp.3-10
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• 2002

유기 전계발광 소자는 발광성 유기화합물을 양극과 음극사이에 형성한 후 전기적으로 여기시켜 그 발광을 이용하는 디스플레이로 1960년도에 처음 전기 적 발광현상이 안트라센 물질에서 처음 보고되었다[1]. 그 후 1987년에 코닥(Kodak)사의 Tang에 의해 적층형 유기 전계발광 소자가 처음 연구되어 소개된 후 실용화를 목표로 활발히 연구되기 시작하였으며[2], 1990년도 들어서는 유기물 재료 중에 전도성 고분자형 재료의 전기적 발광현상이 영국의 케임브리지 대학에서 보고되어 고분자형 유기 전계발광 소자연구가 진행되기 시작하였다[3]. 유기 전계발광 디스플레이는 평판 디스플레이의 한 종류로서 저전압 구동, 박형, 자체발광에 인한 고인식성 및 넓은 시야각, 빠른 응답속도 등의 많은 장점을 갖고 있어 현재 널리 사용되는 액정 디스플레이의 결점을 해결해줄 수 있는 차세대 디스플레이로 최근 들어 매우 높은 관심을 받고 있으며 연구개발 또한 가장n 활발한 분야로 알려져 있다 현재는 저분자형 유기물을 사용하는 저분자 유기 전계발광 소자와 전도성 고분자를 사용하는 고분자 유기 전계발광 소자가 전자발광 디스플레이 연구의 두 분야로 경쟁하면서 연구가 진행되고 있다. 이에 1990년도 후반부터 디스플레이로의 연구가 일본에서부터 활발히 진행되면서 수동형 (Passive Matrix) 구동의 유기 EID가 일본의 Pioneer,한국의 삼성 SDI등에 의해서 상업화되었다. 현재는 카오디오나 핸드폰 등에 이미 채용이 되고 있으며 일반인들이 쉽게 볼 수 있는 디스플레이로 바뀌어가고 있다. 또한 향후 중대형 디스플레이로 상업화하기 위하여 일본의 Sony, Sanyo, Toshiba, 한국의 삼성 SDI 등에서 능동구동 유기 EL (Active Matrix OLED (AM OLED))를 경쟁적으로 개발하고 있다. (그림 1 참조)유기 ELD는 이와 같이 빠른 속도로 발전하고 있으며, 향후 몇 년 내에 우리 주변의 일상적 인 디스플레이로 등장할 것으로 판단된다. 본 보고서에서는 현재 실용화가 급속히 진전되고 있는 유기 전계발광 디스플레이의 소자구조, 발광기구. 소자특성, 각종 재료, 풀컬러화 기술, 구동방법등에 대한 기술개요와 국내외 기술동향에 대하여 소개하고자 한다.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.1
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• pp.1-9
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• 2008

Soft tissue tumor classifications should be an important part of radiology, oncology and, for clinicians and pathologists, they provide diagnostic instruction and prognostic guidelines. In soft tissue tumor classification systems, the World Health Organization (WHO) classifications have become dominant, enabled by the timely publication of new 'blue books' which included detailed text and numerous good illustrations. The new WHO classification of soft tissue tumors was introduced in 2002. Because the classification represents a broad consensus concept, it has gained widespread acceptance around the globe. This article reviews the changes which were introduced the adipose tumors, fibroblastic/myofibroblastic tumors, so-called fibrohistiocytic tumors, smooth muscle tumors, pericytic tumors and skeletal muscle tumors which have been first recognized or properly classified during the past decade.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.539-543
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• 2012

Cellulose Electro-Active Paper (EAPap) is attractive as a biomimetic actuator because of its merits: it is lightweight, operates in dry conditions, has a large displacement output, has a low actuation voltage, and has low power consumption. Cellulose is regenerated so as to align its microfibrils, which results in a piezoelectric paper. When chemically bonded and mixed with carbon nanotubes, titanium oxide, zinc oxide, tin oxides, the cellulose EAPap can be used as a hybrid nanocomposite that has versatile properties and that can meet the requirements of many application devices. This paper presents trends in recent research on the cellulose EAPap, mainly on material preparation and its use in devices, including biosensors, chemical sensors, flexible transistors, and actuators. This paper also explains wirelessly driving technology for the cellulose EAPap, which is attractive for use in biomimetic robotics and micro-aerial vehicles.

• Research in Plant Disease
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• v.21 no.3
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• pp.161-179
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• 2015

Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.4
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• pp.35-41
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• 2002

To solve the large scale optimization problem approximately, various approaches have been introduced. They are mainly based on recent research advancement of simulations for evolutions, flocking, annealing, and interactions among organisms on artificial environments. The typical ones are simulated annealing(SA), artificial neural network(ANN), genetic algorithms(GA), tabu search(TS), etc. Recently the particle swarm optimization(PSO) has been introduced. The PSO simulates the process of birds flocking or fish schooling for food, as with the information of each agent Is share by other agents. The PSO technique has been applied to various optimization problems of which variables are continuous. However, there are seldom trials for visualization of searching process. This paper proposes a new visualization tool for searching process particle swarm optimization(PSO) algorithm. The proposed tool is effective for understanding the searching process of PSO method and educational for students.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.59-59
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• 2001

전보에서 발표한 바와 같이, 대상 라이너지 제조공장의 습부 운전조건이 지극히 악화되어 있으며 초지 시스템이 지종교체 등의 충격에 전혀 완충작용을 못하는 이유로 는 용수를 포함한 지료의 전하특성을 조절해주지 못하기 때문인 것으로 판단되었다. 특 히 양이온성 고분자로서 유일하게 사용하고 있는 보류향상제가 적절히 작용하지 못하 기 때문에 보류도가 저하되고, 제품내에 보류되지 못한 다량의 미세분이 백수 중에 존 재함으로서 결과적으로 지료의 전기적 특성을 더욱 악화시키는 악순환이 되풀이 되는 것으로 판단되었다. 이와 같이 강하게 음으로 하전된 지료의 전기적 특성을 조절하기 위해서는 양이온성 고분자의 사용량을 증가시키거나 고분자의 전하밀도 또는 분자량을 변화시켜 보는 것이 일반적인 습부첨가제 사용방법이라고 할 수 있다. 따라서 대상 습부공정의 조업조건을 호전시키기 위해서는 적절한 보류향상시스 템의 적용이 가장 시급한 현안이라고 판단되어 선규 보류제의 현장적용시험을 수행한 결과, 백수의 COD와 미세분이 격감하고 탈수성이 향상되어 습부공정의 운전조건이 호 전됨을 관측할 수 있었다. 그러나 2달 이상에 걸친 보류제 현장적용시험 기간 중에 생 산된 라이너지의 제반 물성들은 별다른 변화를 관측할 수 없었다. 이는 적용된 보류제 의 상당 부분이 계내의 미세분과 작용하여 소모되기 때문으로 판단되었다. 본 연구에서는 보류제의 투입 이전에 보류제와는 상대적으로 저분자량과 고 전 하밀도를 가진 고분자 전해질 4종을 사용하여 라이너지 지료의 전하를 중화시키고자 하였으며, 이러한 공정으로 생산된 라이너지의 물성변화를 관측하였다. 물성으로는 파 열강도, 압축강도, 습윤인장강도 및 염료 고착능력 등을 살펴보았다.시아노에틸화한 PYA가 안정된 분자구조를 유지하고 있음을 확인할 수 있었다. 시아노에틸화한 PYA용액의 점탄성 평가를 위하여 storage modulus와 loss modulus 를 분석하였다. 일반적 유변특성 평가 결과 PYA용액은 shear-thinning, pseudoplastic 한 특성을 나타내어 표면사이즈 공정에서의 적용 가능성을 확인할 수 있었다. 사용하는 통계기법 중의 하나인 주성분회귀분석을 실시하였다. 주성분 분석은 여러 개의 반응변수에 대하여 얻어진 다변량 자료의 다차원적인 변 수들을 축소, 요약하는 차원의 단순화와 더불어 서로 상관되어있는 반응변수들 상호간 의 복잡한 구조를 분석하는 기법이다. 본 발표에서는 공정 자료를 활용하여 인공신경망 과 주성분분석을 통해 공정 트러블의 발생에 영향 하는 인자들을 보다 현실적으로 추 정하고, 그 대책을 모색함으로써 이를 최소화할 수 있는 방안을 소개하고자 한다.금 빛 용사 둥과 같은 표면처리를 할 경우임의 소재 표면에 도금 및 용 사에 용이한 재료를 오버레이용접시킨 후 표면처리를 함으로써 보다 고품질의 표면층을 얻기위한 시도가 이루어지고 있다. 따라서 국내, 외의 오버레이 용접기술의 적용현황 및 대표적인 적용사례, 오버레이 용접기술 및 용접재료의 개발현황 둥을 중심으로 살펴봄으로서 아직 국내에서는 널리 알려지지 않은 본 기 술의 활용을 넓이고자 한다. within minimum time from beginning of the shutdown.및 12.36%, $101{\sim}200$일의 경우 12.78% 및 12.44%, 201일 이상의 경우 13.17% 및 11.30%로 201일 이상의 유기의 경우에만 대조구와 삭

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.344-351
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• 2009

Purpose: Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. Materials and Methods: In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. Results: We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. Conclusion: We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.288-298
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• 2018

In this study, we surveyed pre- and post-perceptions of fourteen science teachers related to the atmosphere composition of molecules with different masses by the developed test. As a result of the test, the teachers were classified into two types of thoughts; One of them is considered the atmosphere to be a homogeneous solution, and the other is a thought that the composition ratio of the atmosphere was not homogeneous considering the different weights of particles. The two types were reclassified into three categories; one of them is considering large gravity effect, another is considering small gravity effect, and the other is considering medium scale gravity effect. Total six types of thoughts were found from the pre-test. After introducing crosscutting concepts which are related to the composition of atmosphere. The teachers discussed the phenomena with the molecular motion by weights of atoms and temperature, the homogeneity of the solution of air in chemistry domain. They also discussed with the relationship between mass and gravity and distance in physics domain. And the discussion included distribution of the atmosphere, convection phenomena, etc. After the discussion, the teachers changed their pre-conceptions to post-concoctions considering combined perspectives of gravity, mass, temperature, altitude etc. Through these changes, we are able to confirm the importance of crosscutting concepts covered in various disciplines. In the integrated science, we should help teachers to provide students with these types of thinking in order to form a coherent world-view and to carry out inquiry thinking as an intellectual tool.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.295-305
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• 2004

Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.

• Journal of Life Science
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• v.25 no.4
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• pp.473-480
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• 2015

The endoplasmic reticulum (ER) in the eukaryotic cells is the first compartment in the secretory pathway. Almost secretory proteins and membrane proteins are secreted through the ER, in which post-translational modifications occur via diverse signals from the ER lumen to the cytoplasm and nucleus. Only then are correctly-folded proteins secreted to the outside cells. Unfolded proteins that accumulate in the ER cause a kind of intracellular stress, ER stress, and activate an unfolded protein response (UPR) system. The 3 major transducers of the UPR are inositol requiring 1 (IRE1), PKR-like ER kinase (PERK) and activating transcription factor 6 (ATF6), all of which are ER transmembrane proteins. Recently, novel types of a new ATF6 family have been identified. Those commonly have an ER-transmembrane domain, a transcription-activation domain and a basic leucine zipper (bZIP) domain―Luman, OASIS, BBF2H7, CREBH and CREB4. Each factor functions by regulating the UPR in specific organs and tissues. Although the detailed molecular mechanisms of OASIS family members are unknown, in this study we comprehensively introduce these molecular signals.