소형무장헬기 회전형 포탑시스템의 안정화추적 성능 시험기법

남병욱,이호정,조시훈,조성훈,Nam, Byounguk,Lee, Hojung,Jo, Sihun,Cho, Sunghun 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.6

In this paper, we propose a novel method which can be applied to test and verify the stabilization-tracking performance of Gun/Turret Driving System(GTDS) for Light Armed Helicopter(LAH). In real system, GTDS is connected to TADS/SMC and drived to aim at the target with 20mm gun. But each equipment is separately developed during exploratory development stage, so GTDS cannot be tested under real system state. We suggest new configuration of test system for evaluating the stabilization-tacking performance, in which TADS and SMC are replaced by vision acquisition unit and processing unit, respectively.

키넥트 센서를 활용한 투명 디스플레이에서의 사용자 위치에 대한 시계 정합 연구

남병욱,이경호,이정민,Nam, Byeong-Wook,Lee, Kyung-Ho,Lee, Jung-Min,Wu, Yuepeng 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.6

International Hydrographic Organization(IHO) adopted standard S-100 as the international standard Geographic Information System(GIS) that can be generally used in the maritime sector. Accordingly, the next-generation system to support navigation information based on GIS standard technology has being developed. AR based navigation information system that supported navigation by overlapping navigation information on the CCTV image has currently being developed. In this study, we considered the application of a transparent display as a method to support efficiently this system. When a transparent display applied, the image distortion caused by using a wide-angle lens for parallax secure, and the disc s, and demonstrated the applicability of the technology by developing a prototype. 국제 수로기구(IHO)에서는 해양분야에 범용으로 사용 가능한 국제 GIS 표준으로 S-100 표준규격을 채택하였다. 이에 따라 GIS 표준기술 기반의 차세대 항행정보 지원시스템에 대한 기술이 개발되고 있으며, 현재 CCTV 영상에 항행정보를 덧입혀 항행에 지원할 수 있는 증강현실 기반의 항행정보시스템이 개발되고 있다. 이에 본 연구에서는 이 시스템을 효과적으로 지원할 수 있는 방안으로 투명 디스플레이에서의 적용을 고려하였다. 투명 디스플레이 적용 시 시계확보를 위한 광각 렌즈사용으로 인한 영상왜곡, 사용자 위치에서의 CCTV 영상과 투명 디스플레이 투영 이미지의 불일치로 인하여 사용자가 실제 바라보는데 이질감이 발생하므로, 이를 해결하기 위한 시계정합 및 영상보정 방법에 대한 연구를 진행하였으며, 이를 프로토타입으로 개발하여 기술적용의 가능성을 입증하였다.

의사결정트리 학습을 적용한 조선소 블록 적치 위치 선정에 관한 연구

남병욱(Byeong-Wook Nam),이경호(Kyung-Ho Lee),이재준(Jae-Joon Lee),문승환(Seung-Hwan Mun) 대한조선학회 2017 大韓造船學會 論文集 Vol.54 No.5

Tetramethyl Bisphenol - A Polyarylate 의 합성과 Poly ( styrene - co - acrylonitrile ) 과의 상용성에 관한 연구

남병욱(Byeong Uk Nam),엄달호(Dal Ho Um) 한국고분자학회 1992 폴리머 Vol.16 No.6

펠렛형 MWCNT를 사용한 PP/MWCNT 나노복합체 물성 연구

남병욱(Byeong Uk Nam),정동석(Dong Seok Jeong) 한국고분자학회 2011 폴리머 Vol.35 No.1

본 연구에서는 폴리프로필렌(PP)/다중벽 탄소나노튜브(MWCNT)복합체를 이축압출기를 사용하여 펠렛형 MWCNT를 20 wt%까지 함량별로 제조하고, MWCNT가 20 wt% 첨가된 복합체를 마스터배치(M/B)로 사용하여 함량별로 다시 PP와 컴파운딩하여 희석하였다. PP/MWCNT 복합체는 함량 변화에 따라 전기전도도, 열전도도, 모폴로지, 열적, 고체 점탄성, 기계적 성질을 조사하였고, 또한 희석된 PP/MWCNT 복합체와 1단계 PP/MWCNT 복 합체간의 물성을 비교하였다. 전기전도도와 열전도도는 MWCNT의 함량이 3 wt% 일 때 percolation threshold 현상을 보였고, M/B로 제조된 복합체가 더 우수한 전도도를 보였다. 복합체의 MWCNT 함량이 증가하면 비등온 결정화 온도 및 열분해 온도가 증가하였다. 모폴로지를 통하여 M/B로 제조된 복합체의 MWCNT 길이가 짧아진 것을 확인하였고, 이는 기계적 물성의 향상에 도움을 준 것으로 나타났다. Polypropylene/multi-walled carbon nanotube(PP/MWCNT) composites along with various MWCNT contents up to 20 wt% were prepared by a twin screw extruder. Nanocomposites having 20 wt% MWCNT as a master batch(M/B) were diluted with PP by way of melt compounding. The electrical/ thermal conductivity, morphology, thermal/viscoelastic/mechanical properties were investigated with the variation of MWCNT contents. Also, we compared some properties between 1-step PP/MWCNT and the diluted PP/MWCNT composites. The percolation threshold of electrical and thermal conductivity was measured at about 3 wt% MWCNT. And conductivity of diluted PP/MWCNT composites were superior to those of PP/MWCNT composites. The non-isothermal crystallization temperature and thermal decomposition temperature appeared at higher temperatures with increasing MWCNT contents. Morphology showed that length of MWCNT in diluted PP/MWCNT composites was shortened by twice melt blending, which contributed to improve the tensile strength of PP/MWCNT composites.

Comonomer 도입한 상용화제가 Polypropylene / clay 나노복합재료에 미치는 영향

남병욱(Nam, Byeong-Uk) 한국산학기술학회 2007 한국산학기술학회논문지 Vol.8 No.2

본 연구에서는 극성 monomer인 HEMA와 GMA 를 이용하여 PP를 개질한 상용화제를 제조하였고, 이를 이용하여 용융컴파운딩 방법에 의해 PP계 나노복합재료를 제조하였다. 제조한 나노복합재료는 comonomer 도입 유무에 따른 상용화제 효과를 관찰하고자 XRD를 이용하여 분산성을 확인하였고, UTM등을 통하여 기계적 성질을 측정하였다. XRD 분석 결과, comonomer가 도입된 상용화제를 이용하여 제조된 나노복합재료는 Clay의 층간삽입이 개선되어 분산성이 향상됨을 볼 수 있었다. 또한, 기계적 성질 평가 결과 GMA monomer로 개질된 상용화제를 사용하여 제조한 나노복합재료가 굴곡탄성률과 충격강도 측면에서 더 향상된 결과를 보여주었다. Comonomer를 도입하여 제조한 나노복합재료는 Comonomer를 도입하지 않은 나노복합재료에 비해서 그라프팅 수율이 향상되었고, 반면에 용융지수가 감소되는 경향을 보였다. 본 연구에서 제조한 comonomer가 도입된 나노복합재료는 monomer 와 comonomer의 비율이 1:1 인 경우에 가장 향상된 기계적 성질과 분산성을 보임을 확인 할 수 있었다. Nanocomposites prepared by PP(polypropylene) based compatibilizers modified with GMA(Glycidyl methacrylate) and HEMA(Hydroxyethyl methacrylate) were used to investigate the clay dispersion and mechanical properties of them. XRD patterns showed the improvement of dispersion through clay intercalation according to the compatibilizers and comonomer. GMA modified polypropylene gave the best mechanical properties of the nanocomposite with respect to the balance of Flexural modulus (FM) and Notched izod impact strength(IS). Compatibilizers with comonomer commonly have highei grafting yield and lower melt flow rate than those of comonomer free. And they enhanced the clay dispersion and mechanical properties of nano-composites. Optimum ratio of monomer to comonomer for nanocomposites having better mechanical properties is about 1 to 1 ratio.

PLLA/EGMA 블렌드의 모폴로지 및 기계적특성

남병욱 ( Byeong Uk Nam ),정동석 ( Dong Seok Jeong ),장미옥 ( Mi Ok Jang ),홍채환 ( Chae Hwan Hong ) 한국공업화학회 2010 응용화학 Vol.14 No.1

PLA is too brittle for room-temperature applications. Therefore, It can be toughened through blending with other polymers. In this study, PLLA/EGMA blends were prepared by melt blending with biodegradable poly-L-lactic acid (PLLA) and Poly(ethylene-co-glycidyl methacrylate) (EGMA). Blend compositions of PLLA/EGMA were 100/0, 25/75, 50/50, 75/25 and 0/100, respectively. The morphology and mechanical properties were characterized by FESEM, DMA, UTM and Izod impact tester. Throughout FESEM image, we observed that domain was well diffused into matrix. DMA and Izod impact test data show that storage modulus of room temperature with increasing EGMA content decreased, and impact strength increased. The tensile strength and flexural modulus were decreased with increasing the content of EGMA in them.

용융 블렌딩법에 의한 PPC/EVAc 블렌드의 모폴로지 및 열적 특성

남병욱 ( Byeong Uk Nam ),정동석 ( Dong Seok Jeong ),이범석 ( Bum Seok Lee ) 한국공업화학회 2010 응용화학 Vol.14 No.1

PPC (Polypropylene carbonate) has been an charming green material due to containing carbon dioxide. PPC is made from copolymerization of CO2 with propylene oxide (PO) using a catalyst. However this polymer has fool mechanical property and relatively low glass transition temperature (Tg) and thermal decomposition temperature. Therefore, we blended PPC and EVAc (ethylene vinyl acetate) with overall compositions to enhance mechanical property and thermal property. Mechanical property and thermal property of PPC/EVAc blends was investigated by DMA (Dynamic Mechanical Analyzer) and TGA (Thermogravimetric analysis) respectively. Compatibility of PPC/EVAc blends was proved by FESEM (Field Emission Scanning Electron Microscope). As a result, we could find all compositions of PPC/EVAc blends are immiscible. However we could see thermal stability is improved as EVAc content increased.

Butyllithium과 Hexyllithium을 이용한 다중벽 탄소나노튜브의 분산 특성 평가

남병욱 ( Byeong Uk Nam ),유정현 ( Jeong Hyun Ryu ) 한국공업화학회 2010 응용화학 Vol.14 No.1

Carbon nanotubes (CNTs) are difficult to disperse in solvents and polymer matrices. Therefore, CNTs have need to do modification from functional groups. In this study, to improve the CNT`s dispersion, we tried to modify the CNT`s surface by butyllithium and hexyllithium solution with multi-walled carbon nanotubes (MWNTs). To find the addition of small functional groups, we analyzed Raman spectrometer and thermogravimetric analysis (TGA) and used various solvents and investigated the dispersity. As a result, functional groups of attached the CNT`s surface are confirmed through Raman and TGA. A small amount of functionalized-MWNTs is dispersed only in chloroform and tetrahydrofuran.

PLA Stereocomplex의 제조 및 열적 특성

남병욱 ( Byeong Uk Nam ),정동석 ( Dong Seok Jeong ),장미옥 ( Mi Ok Jang ),홍채환 ( Chae Hwan Hong ) 한국공업화학회 2010 응용화학 Vol.14 No.1

Polylactide (PLA) is considered a good alternative to fossil fuel based plastics as it is biodegradable and nontoxic to human. However PLA crystallize at a very low rate and has a relatively low melting temperature (Tm) in comparison with other commercial polymers. PLLA/PDLA stereocomplex has been expected to be potential high-performance polymer, because it shows its Tm at 220℃ which is 50℃ higher than homo-PLA. In this work, Thermal properties and crystallization behaviors of stereocomplex were analyzed by using DSC (Differential Scanning Calorimetry), WAXD (Wide angle X-ray scattering) and Polarized microscope. We could find that stereocomplex crystallites exhibit much higher spherulite growth rate. Also, thermal stability is maximized when a 50/50 blend is used.