• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1253-1272
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• 2010

In this paper, we propose a new affine shape adaptation scheme for the affine invariant feature detector, in which the convergence stability is still an opening problem. This paper examines the relation between the integration scale matrix of next iteration and the current second moment matrix and finds that the convergence stability of the method can be improved by adjusting the relation between the two matrices instead of keeping them always proportional as proposed by previous methods. By estimating and updating the shape of the integration kernel and differentiation kernel in each iteration based on the anisotropy of the current second moment matrix, we propose a coarse-to-fine affine shape adaptation scheme which is able to adjust the pace of convergence and enable the process to converge smoothly. The feature matching experiments demonstrate that the proposed approach obtains an improvement in convergence ratio and repeatability compared with the current schemes with relatively fixed integration kernel.

• Journal of Welding and Joining
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• 제35권2호
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• pp.13-22
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• 2017

In laser full penetration welding process, full penetration hole(FPH) is formed as a result of force balance between the vapor pressure and the surface tension of the surrounding molten metal. In this work, a three-dimensional numerical model based on a conserved-mass level-set method is developed to simulate the transport phenomena during laser full penetration welding process, including full penetration keyhole dynamics. Ray trancing model is applied to simulate multi-reflection phenomena in the keyhole wall. The ghost fluid method and continuum method are used to deal with liquid/vapor interface and solid/liquid interface. The effects of processing parameters including laser power and scanning speed on the resultant full penetration hole diameter, laser energy distribution and energy absorption efficiency are studied. The model is validated against experimental results. The diameter of full penetration hole calculated by the simulation model agrees well with the coaxial images captured during laser welding of thin stainless steel plates. Numerical simulation results show that increase of laser power and decrease of welding speed can enlarge the full penetration hole, which decreases laser energy efficiency.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.111-112
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• 2013

본 논문에서는 최근 증가하고 있는 차량의 질서 위반 행위 및 과태료 체납, 대포차 등에 대한 문제를 보다 효율적으로 해결하기 위하여 이동이 간편한 스마트 기기를 통하여 차량의 번호판을 인식하고 관리할 수 있는 시스템을 제시하고자 한다. 영상 촬영 기능과 데이터 전송 기능을 가지고 있는 휴대용 단말기를 소지한 사용자가 자동차의 번호판을 촬영했을 시 자동차 번호판을 인식하고 촬영된 영상과 차량 번호에 대한 데이터를 원격지 서버로 전송하여 차량 소유자에 대한 과태료 체납여부, 위반행위 등을 조회하여 해당 차량에 대한 정보 등을 신속하게 확인하고 현장에서 복합적으로 대응할 수 있는 시스템을 개발하고자 한다. 본 논문에서 제시할 주요한 기능은 영상처리를 통한 차량 번호판 인식과 인식된 차량 번호 정보와 번호판 영상 정보를 원격지 서버로 전송하여 정보를 관리 할 수 있는 시스템을 제시하고자 한다.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2014년도 제50차 하계학술대회논문집 22권2호
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• pp.423-425
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• 2014

스마트기기의 발달과 보급의 확산과 함께 모바일 인터넷 등 통신서비스 환경이 발전함에 따라 이러닝 환경의 고도화가 진행되면서 유비쿼터스러닝, 모바일러닝을 넘어 스마트 디바이스와 이러닝 연관 신기술이 융 복합된 새로운 형태의 교육 시스템인 스마트러닝으로 발전하고 있다. 하지만 현재 다양한 스마트 디바이스 기반의 스마트러닝 서비스를 통해 교육 콘텐츠를 학습자에게 제공하기 위해서는 기존 이러닝 콘텐츠의 구조 개선이 불가피한 상황이며 콘텐츠의 재사용 가능성, 접근성, 상호운용성, 항구성 및 질적 수월성의 향상을 위한 스마트러닝 표준화가 요구되고 있다. 이에 본 논문에서는 기존 이러닝 콘텐츠를 통한 스마트러닝을 구현하기 위한 방안으로 EPUB 3.0 표준을 활용한 스마트러닝 솔루션을 제안하고자 한다.

• 건축역사연구
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• 제27권2호
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• pp.17-28
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• 2018

This study explores the space and society of Seorin-bang(瑞麟坊), using the Hanseong-bu family registry from the Gwangmu period to demonstrate the urban organizational units used during the late Joseon dynasty known as Seo(署)-Bang(坊)-Gye(契)-Dong(洞)-Tong(統)-Ho(戶). It seeks to examine how Seorin-bang's space and society changed with time. First, the study offers approximate demarcation for Gye and Dong through spatial verification of Bang-Gye-Dong-Tong-Ho of Seorin-bang in late Joseon Dynasty, whose precise locations were formerly undetermined. Second, it explores the relationships between Bang-Gye-Dong-Tong-Ho which has been widely understood to be hierarchical by previous studies, and classifies the relationship dynamics between Gye and Dong into four types. Third, the study finds that Seorin-bang retained much of its urban structure including roads, plots, and streams and maintained stable population distribution under the Japanese colonial rule, and continuously served as place of residency for many throughout the Gwangmu period. This study has major implications in that it illustrates space and society of Seorin-bang by converting the family registry from the late Joseon Dynasty into spatial data, and observes its changes subsequent to the Japanese colonial rule.

• Journal of the Optical Society of Korea
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• 제20권5호
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• pp.557-562
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• 2016

In this paper, for the first time, the transmission performances of long-haul 100-Gb/s direct detection optical OFDM (DDO-OFDM) and coherent optical OFDM (CO-OFDM) wavelength division multiplexing (WDM) systems are compared by simulation. It provides specific guides for system parameter selection to get a high-performance and cost-effective OFDM WDM system. Specifically, the comparison involves three aspects: launched power is investigated to achieve better system performance; laser linewidth is numerically investigated to choose cost-effective laser; system dispersion tolerances with different laser linewidths are analyzed to further reveal the advantages and disadvantages of these two detecting methods, direct detection and coherent detection, in long-haul OFDM WDM system.

• Journal of Power Electronics
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• 제17권3호
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• pp.756-765
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• 2017

The control of the power conversion system (PCS) in a battery energy storage system has a challenge due to the existence of grid impedance. This paper studies an impedance model of an LCL-based PCS in the d-q domain. The feature of a PCS connected to a weak grid is unveiled by use of an impedance model and a generalized Nyquist criterion. It is shown that the interaction between grid impedance and the PCS destabilizes the cascaded system in certain cases. Therefore, this paper proposes a novel control method that adopts virtual resistors to overcome this issue. The improvement in the control loop leads the PCS to a more stable condition than the conventional method. Impedance measurement is implemented to verify the correctness of the theoretical analysis. Experimental results obtained from a down-scaled prototype indicate that the proposed control method can improve the performance of the PCS under a weak grid.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.810-819
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• 2016

Uncoordinated charging of large-scale electric vehicles (EVs) will have a negative impact on the secure and economic operation of the power system, especially at the distribution level. Given that the charging load of EVs can be controlled to some extent, research on the optimal charging control of EVs has been extensively carried out. In this paper, two possible smart charging scenarios in China are studied: centralized optimal charging operated by an aggregator and decentralized optimal charging managed by individual users. Under the assumption that the aggregators and individual users only concern the economic benefits, new load peaks will arise under time of use (TOU) pricing which is extensively employed in China. To solve this problem, a simple incentive mechanism is proposed for centralized optimal charging while a rolling-update pricing scheme is devised for decentralized optimal charging. The original optimal charging models are modified to account for the developed schemes. Simulated tests corroborate the efficacy of optimal scheduling for charging EVs in various scenarios.

• 대한한방내과학회지
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• 제12권1호
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• pp.166-182
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• 1991

This study has been carried out to investigate the cause and symptom of Hae su (咳嗽) cause by a cold referring to 25 literature. 1. Cause : wind (風), cold (寒), heat (署), moisture (濕), dryness (燥), fire (火). It appears to cause double and above. 2. Symptoms : PunghanHaeSu (風寒咳嗽) ; HaeSu (咳嗽), Balyul (發熱), DamHueSaegBaeg (痰稀色白), Hu Yang Sung Tag (喉痒聲濁), BiSaegYuChe (鼻塞流涕), OhPungHan (要風寒), DooShinTong (頭身痛), TaeBaqBaeg (笞薄白), Maeg Bu Gin (脈浮緊). PungYeulHaeSu (風熱咳嗽) ; HaeSu (咳嗽), DamJo (痰稠), SaegHwang (色黃), KaegChulBulSang (喀出不痰), KuKallnTong (口瀉咽痛), BalYeul (發熱), OhPungYuHan (要風有肝), HogYuDuTong (或有頭痛), TaeBagHwang (笞薄黃), Maegbusag (脈浮數). JoYeulHaeSu (燥熱咳嗽) ; KunHaeMuDarn (乾咳無痰), HogDamJungDaeHyulSa (或痰中帶血絲), HaelnHungTong (咳引胸痛), BiJolnKun (鼻燥咽乾), pliogyuOhPungBalYeul (或要風發熱), TaeBagHqangIKun (笞薄黃而乾), MaegSeSag (脈細數). 3. Treatment ; PungHanHaeSu ; SoPungSanHan (疏風散寒), Sun PaeJiHae (宣肺止咳), PungYeulHaeSu ; SoPungchungYeul (疏風淸熱), SunPaeJiHae (宣肺止咳), JoYeulHaeSu; CheongPoeYunJo (淸肺潤燥), SaengJinJiHae (生津止咳). Basing on the literature research, I found that Hae Su (咳嗽) caused by a cold belong to category of YugEum(六淫).

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.211-214
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• 2008

신기전은 고려말 최무선에 의해 주화로 개발되었다. 조선시대로 넘어와 세종 30년(1448년) 총통등록(銃筒謄錄)이 편찬되면서 신기전으로 명칭이 바뀌었고, 그 크기와 용도에 따라서 소 중 대 산화 신기전으로 구분이 되었다. 이 중 대신기전은 15세기 개발되었던 로켓형 화기 중에 세계 최대, 최고의 성능을 자랑한다. 본 연구에서는 대신기전을 복원하기 위하여 추진기관인 약통의 재질적 특성과 구조적 특성에 대해 규명해 보았다.