http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Recognizable-Image Selection for Fingerprint Recognition With a Mobile-Device Camera
Dongjae Lee,Kyoungtaek Choi,Heeseung Choi,Jaihie Kim IEEE 2008 IEEE Transactions on Cybernetics Vol.38 No.1
<P>This paper proposes a recognizable-image selection algorithm for fingerprint-verification systems that use a camera embedded in a mobile device. A recognizable image is defined as the fingerprint image which includes the characteristics that are sufficiently discriminating an individual from other people. While general camera systems obtain focused images by using various gradient measures to estimate high-frequency components, mobile cameras cannot acquire recognizable images in the same way because the obtained images may not be adequate for fingerprint recognition, even if they are properly focused. A recognizable image has to meet the following two conditions: First, valid region in the recognizable image should be large enough compared with other nonrecognizable images. Here, a valid region is a well-focused part, and ridges in the region are clearly distinguishable from valleys. In order to select valid regions, this paper proposes a new focus-measurement algorithm using the secondary partial derivatives and a quality estimation utilizing the coherence and symmetry of gradient distribution. Second, rolling and pitching degrees of a finger measured from the camera plane should be within some limit for a recognizable image. The position of a core point and the contour of a finger are used to estimate the degrees of rolling and pitching. Experimental results show that our proposed method selects valid regions and estimates the degrees of rolling and pitching properly. In addition, fingerprint-verification performance is improved by detecting the recognizable images.</P>
Model Predictive Control for an Aerial Manipulator Opening a Hinged Door
Dongjae Lee,Dohyun Jang,Hoseong Seo,H.Jin Kim 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10
Aerial manipulation has been widely studied to be employed in various tasks such as exploration and transportation. To incorporate aerial manipulation into more sophisticated tasks like pulling or pushing a heavy cargo, an active interaction with surrounding structures should be considered. Unlike physical contact with a static structure which was mainly studied in previous papers, interaction with a movable structure requires a consideration of dynamics of the structure which makes the scenario more complex. In this paper, an aerial manipulator opening a hinged door is presented. Coupled dynamics between an aerial manipulator and a hinged door is derived, and a model predictive control (MPC) algorithm using iterative Linear Quadratic Regulator (iLQR) method for the derived dynamic equation is proposed. Through our proposed control strategy, sub-optimal state and input trajectories robust to model uncertainties while satisfying input constraints are generated. Our dynamic model and control algorithm are validated through simulations.
Lee, Jun Hyuk,Choi, Gwan H.,Park, Kyung Jin,Kim, Dongjae,Park, Juhyun,Lee, Seungwoo,Yi, Hyunmin,Yoo, Pil J. The Royal Society of Chemistry 2019 Journal of Materials Chemistry C Vol.7 No.23
<P>Colloidal photonic crystals (CPCs), which possess intrinsic colourization characteristics due to their internal periodic structure, have been extensively exploited for various optical applications. However, conventional droplet-based synthesis of CPCs has shown simple structure and mono-colour generating properties since they generally require a protective shell as the outermost confining layer, and the lattice spacing inside the CPCs is invariantly determined, which hinders further tunability for structural and optically responsive properties. To enhance the tunability for structural and optically responsive properties of CPCs, here, we present a means to induce a spontaneous core-hatching process of selectively removing the CPC-encapsulating oil layer in double emulsion droplets by harnessing interfacial instability. By virtue of the reinforced interconnectivity between colloidal polyvinylpyrrolidone (PVP)-decorated polystyrene (PS) nanoparticles, isolated CPCs can retain their structural integrity even without a protective outer shell. As a result, the hatched CPCs can be further re-ordered into a core-shell-like structure having dual internal spacings and dual-colour generation properties. PVP chains decorated on the PS nanoparticles dictate the lattice spacing not only through solvent swelling but also by imparting structural stability <I>via</I> formation of hydrogen bonds. Furthermore, the degree of hatching of CPCs can be modulated to either core-shell-like CPCs (complete hatching) or Janus-like CPCs (partial hatching). Therefore, the work presented here offers a new approach to create uniquely structured and multicoloured CPCs with stimulus responsiveness while fully utilizing the advantages of the double emulsion templating method.</P>
Correlation Between the Optical and the Structural Properties in SrZrO3 Nanocrystals
Lee Dongjae,이윤상 한국물리학회 2012 새물리 Vol.62 No.10
We used optical and photoluminescence spectroscopic techniques to investigate the optical and the structural properties of SrZrO_3nanocrystals (NCs) synthesized by using the combustion method. As-synthesized SrZrO_3 NCs were post-annealed at various annealing temperatures and under various ambient conditions. The absorption spectra of SrZrO_3 NCs are composed of a fundamental bandgap feature and an in-gap state just below it. With increasing annealing temperature, the bandgap of the NCs becomes larger, and the in-gap state absorption becomes weaker. At the same time, the violet-blue emission, which is clearly identified even at room temperature, is dramatically suppressed. These optical characteristics are in accord with the development of the peaks shown in the X-ray diffraction pattern with increasing annealing temperature. We also examined the possible contribution of the SrCO_3 impurity phase to the optical properties of the SrZrO_3 NCs.
Chronic osteomyelitis with septic arthritis caused by Scedosporium apiospermum
( Dongjae Lee ),( Sun Hee Park ),( Joonhong Park ),( Taijoon Ahn ) 대한내과학회 2015 대한내과학회 추계학술대회 Vol.2015 No.1
We present a rare case of chronic recurrent septic arthritis of knee joint with chronic osteomyelitis caused by Scedosporium apiospermum. A 67-year-old man was admitted to the hospital after sustaining degloving injury of left lower leg with a farm tractor. Wound infection followed injury and coryneform bacteria grew on wound culture of left leg. Despite repeated debridement and prolonged antibiotic therapy, knee swelling and pain recurred. Once infection signs and symptoms resolved after a year-long treatment, he underwent knee joint replacement surgery. One week after joint replacement, fluctuations were noticed on the lateral side of proximal tibia, then incisional debridement was performed. Wound culture of 4 different sites showed the growth of mould, which was later identified as Scedosporium apiospermum by using RNA sequencing of the 18s ribosomal RNA. It was presumed that S. apiosperum was inoculated when he sustained the injury. He received voriconazole without removing prosthesis and infection signsregressed. S. apiospermum is an unusual pathogen of bone and joint infection. Fungal joint infection is not easily diagnosed clinically and difficult to isolate the pathogen. Early diagnosis will reduce morbidity and mortality. Careful suspicion of fungal infection in case of recurrent chronic bone and joint infection will improve the prognosis of patients.