밀리미터파대역(W-대역)공대지 레이다의 이중편파 채널을 활용한 지상 표적 식별 기법에 관한 연구

박성호,공영주,유성현,윤정숙,Park, Sungho,Kong, Young-Joo,Ryu, Seong-Hyun,Yoon, Jong-Suk 한국인터넷방송통신학회 2018 한국인터넷방송통신학회 논문지 Vol.18 No.3

In this paper, we propose a method for recognizing ground target using dual polarization channels in millimeter waveband air-to-surface radar. First, the Push-Broom target detection method is described and the received signal is modeled considering flight-path scenario of air-to-surface radar. The scattering centers were extracted using the RELAX algorithm, which is a time domain spectral estimation technique, and the feature vector of the target was generated. Based on this, a DB for 4 targets is constructed. As a result of the proposed method, it is confirmed that the target classification rates is improved by more than 15% than the single channel using the data of the dual polarization channel. 본 논문에서는 밀리미터파대역의 공대지 레이다에서 이중 편파 채널을 활용한 지상 표적을 식별하기 위한 방법을 제안한다. 먼저 공대지 레이다의 조우 상황에서 Push-Broom 표적 탐지 방법을 설명하고 수신 신호를 모델링한다. 시간 영역 스펙트럼 추정 기법인 RELAX 알고리즘을 이용하여 산란점을 추출하고 표적의 특성 벡터를 생성하였다. 그리고 이를 기반으로 각각의 4표적에 대한 DB를 구성하였다. 제안하는 방법으로 표적 식별 시뮬레이션을 수행한 결과 이중 편파 채널의 데이터를 이용하면 단일 채널에 비해서 표적 식별률이 최대 15% 이상 높아지는 것을 확인할 수 있었다.

HPA 비선형성을 고려한 DMB 시스템 A의 링크레벨 성능 및 동기화 기법

박성호,차인석,장경희,Park SungHo,Cha Insuk,Chang KyungHi 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.6a

유럽의 Eureka-147에 기반을 둔 DAB(Digital Audio Broadcasting) 서비스를 한 단계 더 발전시킨 형태인 DMB(Digital Multimedia Broadcasting) 서비스는 지상파 DMB 서비스와 위성 DMB 서비스로 구분된다. 이 중 위성 DMB 서비스는 휴대용 수신기나 차량용 수신기를 통하여 다채널 멀티미디어 방송을 시청할 수 있는 새로운 개념의 위성 방송 서비스이다. 본 논문에서는 COFDM(Coded Orthogonal Frequency Division Multiplexing)에 기반을 둔 시스템 A 방식 위성 DMB 시스템의 링크 레벨 성능을 고찰한다. 비선형 특성에 민감한 OFDM 방식을 이용함에 따라 비선형 HPA(High Power Amplifier)가 시스템에 미치는 영향을 분석하고, 이에 대하여 Back-off를 고려한 링크 레벨 시뮬레이션을 수행함으로써, 적절한 back-off 값을 결정한다. 또한 위성 DMB 시스템 A에 적합한 동기화 기법에 대하여 분석 및 검증하고 시간 및 주파수 오프셋의 영향을 고려한 링크 레벨 성능을 분석함으로써 위성 DMB 시스템 A 방식에 대한 전반적인 링크 레벨 성능을 검증한다. The DAB(Digital Audio Broadcasting) service which is based on the Eureka-147 of Europe is developed to DMB(Digital Multimedia Broadcasting) service that is divided into Terrestrial DMB and Satellite DMB. The Satellite DMB is a new broadcasting service, which will service multi-channel multimedia broadcasting by the portable receiver or the vehicle receiver. In this paper, we consider that link level performance of satellite DMB system A which is based on the COFDM(Coded Orthogonal Division Multiplexing). It uses the OFDM method which is sensitive to nonlinearity, so we analyze the effect of the HPA(High Power Amplifier) nonlinearity. And then we define the appropriate back-off value by performing the link level simulation considering back-off effect. Also we consider the effect of frequency and time offset, and then confirm the overall link level performance by analyzing and verifying a suitable synchronization method for satellite DMB system A.

가솔린 엔진에서 스퀴시 형상 적용에 따른 유동 특성 해석

박성호(Sungho Park),오병근(Byoungkeun Oh) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1

Squish flow is well known as an important technology for improving knock limit and performance in spark ignition engines. We have developed a slant squish combustion chamber for a new engine. From IVO to 80deg ATDC, the numerical analysis on three-dimensional, transient in-cylinder flow was performed to understand the squish flow patterns for a slant squish and flat squish configurations and we could prove the advantage of slant squish combustion chamber. Compared with a flat squish, a slant squish has high mean turbulent kinetic energy at the spark timing and produces effective reverse squish flow in the early expansion stroke. Through this study, it is possible to get the physical insight into the desirable squish flow patterns at spark timing. Experimental results show that HC and NOx are decreased in the slant squish type compared with the flat squish type.

연행록의 전설(傳說)수용 양상과 『일암연기(一庵燕記)』의 글쓰기 방식

박성호 ( Park Sungho ) 온지학회 2016 溫知論叢 Vol.0 No.49

본고에서는 연행 노정에서 만나게 되는 몇 가지 전설들을 취합하여 그런 전설들이 연행록 상에서 전승되는 경향과 그 의미에 대해서 살펴보았다. 그리고 이기지의 『일암연기』가 그러한 경향과는 어떠한 차이를 보이는지 살펴보았다. 이를 위해 枯樹店에 전해오는 `죽은 나무가 살아나면 眞人혹은 眞主가 나타난다`는 이야기, 그리고 송가장의 `송씨가 최후까지 청에 저항하였고 이에 큰 세금을 내게 되어 家勢가 기울었다`는 이야기를 분석했다. 그리고 논거를 보충하기 위해 `산해관에 부서져서 수리되지 않고 있는 성벽은 오삼계가 허문 것`이라는 이야기도 살폈다. 이를 통해 전대 연행록에서 후대 연행록으로 전설들이 전승될 때 변형이 가해진다는 것을 알 수 있었다. 그리고 그러한 변형에는 시대적인 이데올로기(주로 反淸)가 투영되기도 하고 이야기를 좀 더 劇的으로 만들기 위한 화소가 첨가되기도 하는 등 일정한 경향이 존재한다는 사실을 알 수 있었다. 하지만 『일암연기』는 이데올로기의 투영이나 극적인 전개를 위한 화소의 개입을 최소화하고 전설의 진위여부와 세부사항을 파악하는데 중점을 두었다. 그리고 마지막으로 『일암연기』가 『담헌연기』에 끼친 영향을 살펴 소략하게나마 『일암연기』가 가지는 문학사적 의미에 대해서도 살펴보았다. This article collected some legends that can meet on the road of YeonHang(燕行: trip to China) and studies the tendency of legends transmission. And studies the difference of tendency between general YeonHangRok(燕行錄, record of YeonHang) and 『IlAm YeonGi(一庵燕記)』. To perform this study, I collected two legends. First legend is that if the Dead tree revive, the true lord will appear and the story had passed on GoSuJeom(枯樹店). Second legend is that Songs(宋) family resisted against Qing Dynasty(淸) until the end and the story had passed on Songs` castle. And the two legends becomes the subject of analysis. And to complement the basis of an argument, added the legned of SanHaeGwan(山海關) that some part that collapsed but hadn`t repaired was broken by OSamGye(吳三桂) himself. The three legends are varied when transmitted from the previous YeonHangRok to the next YeonHangRok. And there is tendency in variation, the tendency means ideology(mostly sprit of anti Qing Dynasty) is projected to the story and side stories are annexed to make legend more dramatic. However the interference of ideology and annex of side stories are minimized in 『IlAm YeonGi』 and the writer of 『IlAm YeonGi』(=Lee GiJi(李器之)) focused on revealing the fact of legends. The reason that 『IlAm YeonGi』`s characteristic could be shown is because of the status of Lee GiJi, Sons of diplomat, and comparatively young age that could fulfill the curiosity of the writer. And at the end I observed influence of 『IlAm YeonGi』 to Hong DaeYong(洪大容)`s YeonHangRok and proved the meaning of 『IlAm YeonGi』 in the history of literature

소결온도 및 SiO₂ 첨가량에 따른 탄화규소의 마모 특성

박성호(SungHo Park),박원조(WonJo Park),윤한기(HanKi Yoon) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.11

In this study, liquid phase sintered SiC (LPS-SiC) materials were made by hot pressing method. The particle size of nano-SiC powder was 30㎚. Alumina (Al₂O₃), yttria (Y₂O₃) and silica (SiO₂) were used for sintering additives. To investigate effects of SiO₂, ratios of SiO₂ contents were changed by five kinds. Materials have been sintered for 1 hour at 1760℃, 1780℃ and 1800℃ under the pressure of 20㎫. The system of sintering additives which affects a property of sintering as well as the influence depending on compositions of sintering additives were investigated by measurement of density, mechanical properties such as flexural strength, vickers hardness and sliding wear resistance were investigated to make sure of the optimum condition which is about matrix of SiCf/SiC composites. The abrasion test condition apply to load of 20N at 100RPM for 20min. Sintered density, flexural strength of fabricated LPS - SiC increased with increasing the sintering temperature. And in case of LPS-SiC with low SiO₂, sliding wear resistance has very excellent. Monolithic SiC 1800℃ sintering temperatures and 3wt% have excellent wear resistance.

표면경화된 알루미늄합금의 마모 특성에 관한 연구

박성호(SungHo Park),박원조(WonJo Park),허선철(SunChul Huh),이광영(KwangYoung Lee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

Recently, the steel material part used at the automobile and aerospace industries are require to be used lightweight parts. therefore, used material steel have to be a high stress and light, which is an indispensable condition in this field. aluminum alloy is very light and high stress. but many industries are require to more mechanical characteristic. so we need to development research about the aluminum alloy. there are many way for enhance mechanical characteristic of the aluminum alloy. we used the shot peening as way of the enhance mechanical characteristic. The wear test is one of important factors which evaluate the life of the machine. the surface conditions are measured to know the influence wear characteristics by shot peening and influence on material durability wear and friction by shot velocity. test result show the wear characteristics were increased by optimum peening condition. but the wear characteristic were decreased by under peening or overpeening condition. In this study, used a ball on disk type experiment to measure wear less and friction . shot velocity are 40㎧,50㎧ 70㎧ and used specimen are Al7075-T6 and Al6061-T651.

디젤엔진의 터보랙에 대한 실험적 연구

박성호(Sungho Park),장길상(Kilsang Jang),이준호(Joonho Lee),오광철(Kwangchul Oh),고성석(Sungsuk Ko),최재권(Jaekwon Choi),지용준(Yongjun Jee) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5

Improving the performance and the fuel economy of an engine, the reduction of engine size is considered by using a turbocharger or supercharger. But the turbocharged engines have worse transient response than the naturally aspirated engines because it takes a few seconds to get the turbocharger rotate up to high speed. So many technologies are developed to improve turbocharger response: VGT, Twin turbocharger, water-cooled intercooler, and so on. And there are many researches to analyze turbocharger transient phenomenon: optimizing the size of a turbocharger, flow capacity, efficiency, and moment of inertia. This research deals with the transient response of a diesel engine with variable geometry turbocharger and water-cooled intercooler. And it’s focused on intercooler size, WCAC pipe length, and cooling water temperature of the water-cooled intercooler.

쇼트피닝 투사 속도에 따른 Al6061-T651의 압축잔류응력 및 피로특성에 관한 연구

박성호(SungHo Park),허선철(SunChul Huh),박원조(WonJo Park) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.3

Recently, the steel parts used for automobiles and trains are required to be used under higher stress than ever before in need of the weight down. To achieve this requirement of a high strength steel, it must be necessary to decrease the inclusion contents and surface defects such as decarburization, surface roughness etc. In this study, the results of observation on the arc height, surface roughness, hardness, residual stress and fatigue life of a Al6061-T651 shot peened were obtained. Experimental results show that the increase of arc height is tremendous by shot velocity. Also shows that increase of surface roughness, hardness and compressive residual stress, fatigue life of Al6061- T651 by shot velocity.

MoSi₂기 복합재료의 제조과정에 따른 트라이볼로지 특성

박성호(Sungho Park),박원조(Wonjo Park),허선철(Sunchul Huh),이광영(Kwangyoung Lee),윤한기(Hanki Yoon) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this study, monolithic MoSi₂, 20 vol.% SiC particles-reinforced MoS₂ matrix, SiC/MoSi<br/> composite and 20 vol.% ZrO₂ panicles-reinforced MoSi₂ matrix, ZrO₂/MoSi₂ composite was fabricated by hot pressed sintering at 1350℃ under 30 ㎫ during 60 min. Vickers hardness and sliding wear resistance of the monolithic MoSi₂, ZrO₂/MoSi₂ and SiC/MoSi₂ composite was investigated at room temperature. Abrasion tester used a pin-on-disk type and a Si3N4 ceramic ball which used as machine structural materials. The test condition apply to load of 8kgf a 7.5rpm for 6 hours and the effect of hardness is also discussed The ZrO₂/MoSi₂ composite has shown the very excellent wear resistance compared with monolithic MoSi₂ and SiC/MoSi composite at room temperature.<br/>

벤처기업 창업환경 및 기업성장단계가 경영애로사항에 미치는 영향에 관한 실증 연구

박성호(Park, Sungho),양동우(Yang, Dong-Woo) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.1

본 연구는 2012년 벤처기업정밀실태조사 데이터를 기반으로 벤처기업의 창업주 특성 및 기업 성장단계가 기업간 거래 및 경영상 애로사항에 어떠한 영향력이 있는지를 실증적으로 분석하였다. 창업주의 연령과 학력에 따라 기업 간 거래 시 애로사항 발생빈도가 차이가 있는 것으로 나타났다. 창업주의 연령, 학력, 전공 등에서 경영상 애로사항 인식 차이가 있는 것으로 나타났다. 학력은 석사에서, 전공은 인문사회 분야에서 상대적으로 경영상 애로사항이 높은 것으로 분석되었다. 반면, 기업 성장단계에 따라 기업 간 거래 시 애로사항의 발생빈도에 대한 인식은 차이가 없는 것으로 분석되었다. 이는 기업이 성장하는 단계마다 애로사항이 빈번하게 일어남에도 불구하고 루틴하게 해결되고 있는 것으로 판단된다. 그러나 기업의 쇠퇴기 단계에서 경영상 애로사항 인식이 높았다. 이는 기업간 거래 시 쇠퇴기에 있는 업체와 거래를 꺼려하기 때문으로 이는 당연한 결과로 해석된다. This study analyze empirically how the characteristics of a venture business' founder and company development stage will affect on B2B transactions and business management difficulties based on 「2012 Survey of Korea Venture Firms」. According to this study, there are different frequencies of difficulties in B2B transactions depending on the founder's age and educational background as well as different recognitions about business management difficulties with considering the founder's age, educational background, major and other factors. It is analyzed that in educational background factor, master's degree and in major factor, humanities and social science show comparatively frequent business management difficulties. On the other hand, it is analyzed that there is not meaningful difference in the recognition about the difficulty-frequency in B2B transactions in each company growth stage. It is considered that the difficulties occur frequently in every company growth stage but, these types of difficulties are solved routinely. At the Exit phase, however, there is high recognition about business management difficulties as the transaction with the companies in this stage is avoided.