Rectification of elemental image set and extraction of lens lattice by projective image transformation in integral imaging

Hong, Keehoon,Hong, Jisoo,Jung, Jae-Hyun,Park, Jae-Hyeung,Lee, Byoungho The Optical Society 2010 Optics express Vol.18 No.11

<P>We propose a new method for rectifying a geometrical distortion in the elemental image set and extracting an accurate lens lattice lines by projective image transformation. The information of distortion in the acquired elemental image set is found by Hough transform algorithm. With this initial information of distortions, the acquired elemental image set is rectified automatically without the prior knowledge on the characteristics of pickup system by stratified image transformation procedure. Computer-generated elemental image sets with distortion on purpose are used for verifying the proposed rectification method. Experimentally-captured elemental image sets are optically reconstructed before and after the rectification by the proposed method. The experimental results support the validity of the proposed method with high accuracy of image rectification and lattice extraction.</P>

See-through multi-projection three-dimensional display using transparent anisotropic diffuser

Hong, Jong-Young,Park, Soon-Gi,Lee, Chang-Kun,Moon, Seokil,Kim, Sun-Je,Hong, Jisoo,Kim, Youngmin,Lee, Byoungho The Optical Society 2016 Optics express Vol.24 No.13

Two-dimensional and three-dimensional transparent screens based on lens-array holographic optical elements.

Hong, Keehoon,Yeom, Jiwoon,Jang, Changwon,Li, Gang,Hong, Jisoo,Lee, Byoungho Optical Society of America 2014 Optics express Vol.22 No.12

<P>Two-dimensional (2D) and three-dimensional (3D) transparent screens can be created using lens-array holographic optical elements (HOEs). Lens-array HOEs can be used to perform 2D and 3D imaging for Bragg matched images while maintaining the transparent properties of the images in the background scenes. 2D or 3D imaging on the proposed screen is determined by the relative size of an elemental-lens on the lens-array to a pixel on the projected image. The 2D and 3D displays on the lens-array HOEs are implemented by the diffusion of light on each elemental-lens and by taking advantage of reflection-type integral imaging, respectively. We constructed an HOE recording setup and recorded two lens-array HOEs having different optical specifications, permitting them to function as 2D and 3D transparent screens. Experiments regarding 2D and 3D imaging on the proposed transparent screens are carried out and the viewing characteristics in both cases are discussed. The experimental results show that the proposed screens are capable of providing 2D and 3D images properly while satisfying the see-through properties.</P>

Mixed-scale poly(methyl methacrylate) channel network-based single-particle manipulation <i>via</i> diffusiophoresis

Hong, Jisoo,Kim, Beomsang,Shin, Heungjoo The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.30

<P>Despite the unique advantages of nanochannels imparted by their small size, their utility is limited by the lack of affordable and versatile fabrication methods. Moreover, nanochannel-incorporated fluidic devices require micro-sized conduit integration for efficient access of liquid samples. In this study, a simple and cost-effective fabrication method for mixed-scale channel networks <I>via</I> hot-embossing of poly(methyl methacrylate) (PMMA) using a carbon stamp is demonstrated. Due to its high rigidity, PMMA ensures collapse-free channel fabrication. The carbon stamp is fabricated using only batch microfabrication and has a convex architecture that allows the fabrication of a complex channel network <I>via</I> a single imprinting process. In addition, the microchannels are connected to nanochannels <I>via</I> three-dimensional (3D) microfunnels that serve as single-particle-entrapment chambers, ensuring smooth transport of samples into the nanochannels. Owing to the 3D geometry of the microfunnels and the small size of the nanochannels, a solute gradient can be generated locally at the microfunnel. This local solute gradient enables the entrapment of microparticles at the microfunnels <I>via</I> diffusiophoresis, which can manipulate the particle motion in a controllable manner, without any external equipment or additional electrode integration into the channels. To the best of our knowledge, this is the first report of diffusiophoresis-based single-particle entrapment.</P>

Integral floating display systems for augmented reality

Hong, Jisoo,Min, Sung-Wook,Lee, Byoungho The Optical Society 2012 Applied optics Vol.51 No.18

<P>Novel integral floating three-dimensional (3D) display methods are proposed for implementing an augmented reality (AR) system. The 3D display for AR requires a long-range focus depth and a see-though property. A system that adopts a concave lens instead of a convex lens is proposed for realizing the integral floating system with a long working distance using a reduced pixel pitch of the elemental image. An investigation that reveals that the location of the central depth plane is restricted by the pixel pitch of the display device is presented. An optical see-through system using a convex half mirror is also proposed for providing 3D images with a proper accommodation response. The concepts of the proposed methods are explained and the validity of system is proved by the experimental results.</P>

Analysis of the expressible depth range of three-dimensional integral imaging system

Jisoo Hong,Joohwan Kim,Jae-Hyeung Park,Byoungho Lee 한국광학회 2004 Current Optics and Photonics Vol.8 No.2

3D/2D convertible projection-type integral imaging using concave half mirror array.

Hong, Jisoo,Kim, Youngmin,Park, Soon-Gi,Hong, Jong-Ho,Min, Sung-Wook,Lee, Sin-Doo,Lee, Byoungho Optical Society of America 2010 Optics express Vol.18 No.20

<P>We propose a new method for implementing 3D/2D convertible feature in the projection-type integral imaging by using concave half mirror array. The concave half mirror array has the partially reflective characteristic to the incident light. And the reflected term is modulated by the concave mirror array structure, while the transmitted term is unaffected. With such unique characteristic, 3D/2D conversion or even the simultaneous display of 3D and 2D images is also possible. The prototype was fabricated by the aluminum coating and the polydimethylsiloxane molding process. We could experimentally verify the 3D/2D conversion and the display of 3D image on 2D background with the fabricated prototype.</P>

Purification and Characterization of Pasteuricin Produced by Staphylococcus pasteuri RSP-1 and Active against Multidrug-Resistant Staphylococcus aureus

HONG, JISOO,KIM, JONGUK,QUAN, LIN-HU,HEU, SUNGGI,ROH, EUNJUNG ational Association for Food Protection 2018 Journal of food protection Vol.81 No.11

<B>ABSTRACT</B><P>Staphylococcus aureus is an important pathogen implicated in various diseases, including staphylococcal food poisoning. Bacteriocins are considered safe and effective antimicrobial substances for the prevention of the growth of pathogenic bacteria. In this article, we describe the purification and characterization of pasteuricin, a novel bacteriocin produced by Staphylococcus pasteuri RSP-1. A cell-free supernatant of S. pasteuri RSP-1 exerted strong antimicrobial activity against staphylococci, including methicillin-resistant S. aureus (MRSA), and gram-positive bacteria. The loss of antimicrobial activity upon treatment with proteolytic enzymes confirmed the proteinaceous nature of pasteuricin. A rapid and pronounced bactericidal effect of pasteuricin was confirmed by a live-dead bacterial viability assay. To our knowledge, pasteuricin is the first reported S. pasteuri bacteriocin that inhibits S. aureus. Because pasteuricin is characterized by strong antimicrobial activity and high stability, it has potential as an alternative antimicrobial agent to antibiotics.</P>

나노임프린트를 이용한 마이크로-나노 혼합 스케일 PMMA 채널 네트워크 제작공정 개발

홍지수(Jisoo Hong),임영진(Yeongjin Lim),신흥주(Heungjoo Shin) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

In this paper, we present the fabrication of mixed-scale PMMA (polymethyl methacrylate) channels consisting of micro- and nano-channels using simple thermal nanoimprint and thermal bonding processes (microchannels: width = ~ 100 ㎛, height = ~ 8 ㎛; nanochannels: width = ~ 700 ㎚, height = ~ 150 ㎚, length = ~ 100 ㎛). In the nanoimprint process, a monolithic mixed-scale carbon structure was used as a mold. The monolithic carbon mold was fabricated using carbon-MEMS consisting of two-step photolithography processes for patterning a polymer structure and one step pyrolysis process for converting polymer to carbon. In pyrolysis, polymer structures shrank dramatically and thus micro-sized polymer structures could be converted into sub-micro-/nano-sized carbon structures. The shape of the monolithic mixed-scale carbon mold was pressed into a PMMA sheet while the polymer sheet was heated. After demolding the carbon mold from the patterned PMMA sheet, the patterned channel networks on the PMMA sheet was sealed by bonding another thin PMMA sheet to the patterned PMMA sheet with pressure and heat subsequent to an oxygen plasma treatment. The pyrolyzed carbon mold could be easily demolded because of its curved side walls resulting from anisotropic volume reduction in pyrolysis. This special geometry and good robustness of the carbon mold ensured reproducibility in nanoimprint process. PMMA has higher Young’s modulus compared to PDMS (polydimethylsiloxane) that is widely used for the nano-channel fabrication so that the PMMA channels ensure consistent channel fabrication and nanofluidic experiments without channel collapse originated problems.

날씨를 고려한 딥러닝 기반의 개별 가구 에너지 사용 요금 예측

박지수(Jisoo Park),홍승우(Seungwoo Hong),서일홍(Il-hong Suh) 대한전자공학회 2020 전자공학회논문지 Vol.57 No.4

에너지 사용 요금은 가계의 고정적인 지출 항목 중 하나로써, 특히 날씨로 인해 에너지 사용이 급증하는 시기에는 높은 누진율이 적용되어 가계 부담을 키우고 있다. 이에 소비자는 합리적인 에너지 사용을 필요로 하는데, 이를 위해서는 소비자가 고지될 에너지 사용 요금을 사전에 예측하고, 그에 따라 에너지 사용을 조절할 수 있어야 한다. 따라서 본 논문은 딥러닝 기반의 모델을 이용하여 에너지 요금 예측에 큰 영향을 미치는 날씨를 고려한 개별 가구의 월 에너지 사용 요금 예측 방법을 제안하였다. 날씨 정보로는 실험적으로 유의미한 성능 향상을 보인 최저기온, 최고기온, 강수확률, 강수량, 습도, 풍속, 적설량, 전운량이 사용되었으며, 대표적인 딥러닝 기반의 세 가지 모델들(Multilayer Perceptron, Convolution Neural Network, Long-Short Term Memory)을 주어진 문제에 맞게 설계 및 구현하여 Long-Short Term Memory 기반의 모델이 가장 적은 오차를 보이는 것을 확인하였다. 또한, 이러한 결과를 바탕으로 본 논문에서 제안한 방법을 실제 2,234가구의 에너지 사용량 데이터와 기상청의 날씨 데이터에 적용하였을 때 평균 5,110원이라는 작은 오차로 개별 가구의 에너지 사용 요금 예측이 가능함을 실험적으로 입증하였다. Energy bills are one of the household"s fixed expenses. In particular, when energy consumption is soaring due to weather conditions, a progressive rate is applied, which raises household burden. Therefore, consumers need to be rational in their energy use, and for this, they must be able to predict energy expenditure and adjust the energy use accordingly. To this end, in this paper, we propose a prediction method of the monthly energy bill for individual households using a deep-learning-based model, considering the weather, which has an important effect on energy bill prediction. As weather information, minimum temperature, maximum temperature, precipitation probability, precipitation, humidity, wind speed, snow level, and cloud cover are used, which shows an experimentally significant performance improvement. Also, three representative deep learning models (Multilayer Perceptron, Convolution Neural Network, Long-Short Term Memory) are designed and implemented for the given problem, and the model based on Long-short term memory exhibits the lowest error. The proposed method based on these results is applied to the actual energy usage data of 2,234 households and weather data of the Korea Meteorological Administration. The experiment shows that the energy bills of individual households can be predicted with a small average error of 5,110 won (4.28 dollars when the Korean won to the U.S. dollar exchange rate is 1,194 won per dollar) using the proposed approach.