• Polymer(Korea)
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• v.29 no.6
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• pp.543-548
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• 2005

Double-layered spheres play an important role in controlling drug delivery for pharmaceutical application, because of the low initial burst compared with single-layered spheres and targetable delivery to specific organ. But it has drawback in loading drug and controlling size. In this study, we developed double-layered spheres using relatively simple oil-in-water (O/W) solvent evaporation method witw/without ultrasonication and investigated the size variation of the double-layered microspheres on the contents of poly(lactide- co-glycolide) (PLGA). Double - layered spheres were char-acterized by scanning elecron microscope (SEM), camscope, and confocal fluorescence laser microscope (CFLM). Double-layered spheres showed smooth surfaces and obvious difference between core and corona by SEM observation and camscope. We observed the fluorescent core in the double-walled spheres composed of FlTC-dextran and PLGA using CFLM. It was found that the core of the microsphere was dextran and the corona of the fabricate microsphere was PLGA. Also, the more PLGA concentration, the more the size of the fabricating double-layered sphere observed.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.245-248
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• 2016

현대의 항공테러는 단순한 항공기 납치뿐만 아니라 항공기의 공중 폭파, 항공기에 대한 미사일 공격, 공항과 승객에 대한 공격, 그리고 항공 외부 시설에 대한 공격 등 실로 다양한 형태로 자행되고 있다. 항공 교통에서의 불법 방해행위를 사전에 방지하기 위해서는 출발지의 보안 검색이 무엇보다도 중요하며, 이를 위해서 사전 예방적 선제적 항공보안관리 체계 전환, 출입부터 탑승까지 전 과정을 프로세스화한 점검활동 강화, 국제권고기준 항공보안장비 보유와 첨단화 등 미래 변화에 대한 능동적 대처뿐만 아니라 정확한 보안검색과 고객편의의 융합을 통해 세계 최고 공항으로 지향하며, 행동탐지기법의 도입을 통해 일상적이고 포괄적인 보안검색 운영의 약점을 보완하여 항공보안 강화의 토대를 마련해야 하고, 불법 방해행위의 억지를 위해 2015년부터 새롭게 실시하는 국제민간항공기구 상시 모니터링 제도의 항공보안 평가(USAP-CMA) 방식을 적극 검토하여 국정원 공항공사 항공사 등 관련기관 정보 공유, 지속적인 모니터링 및 국내 국제민간항공기구(ICAO) 인증 항공 보안평가관 등과 철저히 대비한 세부 대응 계획을 수립하고 항공보안 전문가 육성을 강구하여야 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.225-232
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• 2001

In this paper, we describe a mechanism that supports the mobility service for VPN(Virtual Private Network) users on MPLS(Multiprotocol Label Switching) network. The MPLS VPN considered in this study is controlled by CE(Customer Edge) routers. In such a VPN, CE routers have additional functions to support mobile VPN users, i.e., Home Agent function, foreign Agent function, Correspondent Agent function. This mechanism is applied when a VPN node moves to other site of the saute VPN, or when it moves to other site of a different VPN, or to a non-VPN site. We perform a simulation study to compare the performance of CE based MPLS VPN with that of PE(Provider Edge) based MPLS VPN with mobility support.

• Journal of IKEEE
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• v.19 no.3
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• pp.349-356
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• 2015

Air Defense Command Control and Alert(ADC2A) system is a system that ensures simultaneity and integrity of air defense operations by combining sensors, weapons and Command and Control(C2) systems over a tactical network to protect forces, facilities and strategic points from enemy's air attack. Improving message processing speed is a very important factor for ADC2A, because it uses high frequency bit-processing of the Army standard KVMF message to communicate with internal and external systems. In this paper we proposed improved method of KVMF message processing for ADC2A system.

• Polymer(Korea)
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• v.29 no.4
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• pp.380-384
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• 2005

Fluoroalkyl methacrylate and acrylic acid were bulk radical copolymerized in the presence of pure sodium montmorillonite or macromer intercalated sodium montmorilonite to get a fluorinated acrylic ionomer/sodium montmorillonite composite, and their physical properties, such as X-ray diffraction pattern, tensile properties, and water uptake, were examined. These composites were used to preparean ionic acrylic polymer-platinum composite (IPMC). The current and deformation responses of these IPMCs by external voltage applied across the platinum electrodes deposited on both sides of IPMC showed that the cation migration from anode to cathode was suppressed in the presence of sodium montmorillonite, causing reduced current and deformation.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.5
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• pp.1-11
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• 1979

Since the second half of 1960's one of the information industry's most vital, yet least-well-understood areas has evolved-Data communications/Computer communications. To successfully realize this field we have to identity and reveal a variety of fundermental characteristics of communications channels and see their high reliability as prerequisites. This paper has accumulated related data from 1973 on, systematically analyzed them and provided some basic back ground and suggestions. Error rate which is the final and external characteristics of communication lines according to channal types, communication types and speed, block length and geographical difference between test points was extensively examined as well as their frequency response and d-c characteristics. The perspective of 9600BPS high speed data communications was also discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.227-229
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• 2016

Drone is demanding more than detaile hardware and software systems because Drone have characteristic flying. If Drone is a plane crash. they have risk of personal injury and property damage. now Drone control core system is preventing a plane crash and flight unsafe flying. The key is to help flying to convert for various external environment. This research prevent a plane crash that system planning to treat six-senser-figure doubly is IMU trouble or a trouble caused by a passing parameters and IMU install to help stability in flying.

• Economic and Environmental Geology
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• v.45 no.4
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• pp.431-440
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• 2012

This study examines the communication status and strategies of geological resource related companies in Korea through the comparison with American companies. Through this analysis, this study is to draw the domestic companies' characteristics and problems on communication, and even to suggest how to execute the communication about geo-technologies at national level. The results indicate that geo-technologies related compaies in Korea don't use a lot of advertising communication as means of providing informations about corporate itself, corporate activities, and it's product, etc. And the companies using advertising communication tend to execute more organization advertising focusing on corporate image than product advertising. The advertising utilized by geological resource related companies is usually targeted at consumers, they don't use advertising endorser actively. And all the companies analyzed in this study have their own website and run it. This study provides some recommendations on communication strategies and executions for various geo-technologies related organizations. (1)Advertising strategies for establishing a specific image (2)Advertising message for understanding about geo-technologies (3)A variety of advertising creative (4)A consistent advertising concept and message strategies (5)A consideration about website in terms of PR (6)Information on website for various stakeholders (7)Providing various information message on website.

• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.41-48
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• 2002

Anisotropy of stiffness, from extremely small strains to post-failure strains, of isotropically consolidated air-pluviated sands in plane strain compression was studied by using the newly developed instrumentation fur small strain measurements, Seven types of sand of world-wide origins were tested, which have been extensively used for research purposes. Stress-strain relationships for a wide range of strain from about 0.0001% to the peak were obtained by measuring axial and lateral strains locally free from the effects of bedding and membrane penetration errors at the specimen boundaries. The result showed that the relationship between the principal stress ratio and the principal strain increment ratio was constant, being rarely affected by the over-consolidation ratio and the confining pressure. Although in the small strain the anisotropy hardly affected the relationship between the principal stress ratio and the principal strain increment ratio, the K value around the peak varied according to the $\delta$ value. In general, Rowe\`s stress-dilatancy equation works fairly well from the small strain to the peak.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.287-298
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• 2020

Air pollution is a severe risk factor in public health. It is not only a cause of a variety of physical disorders but also attributable to mental health problems. This study aimed to investigate the differences on emotions, physical symptoms, future perspectives by perceived air pollution. Sixty-one university students were randomly allocated either to air pollution group (n = 30) or clean air group (n = 31). Participants watched a news video clip of a polluted city or a clean city according to their condition and were asked to imagine as if they were living in the city. Results showed that air pollution group reported increased depression, anxiety, anger and physical symptoms after the exposure. Meanwhile, clean air group showed no significant changes or decrease of them. In addition, air pollution group reported restrained future time perspectives and decreased plan of outdoor activities, while clean air group did not report significant changes after the exposure.