• The KIPS Transactions:PartA
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• v.16A no.4
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• pp.299-306
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• 2009

Hierarchical Folded HyperStar Network has lower network cost than HCN(n,n) and HFN(n,n) which are hierarchical networks with the same number of nodes. In this paper, we analyze embedding between Hierarchical Folded HyperStar HFH($C_n,C_n$) and Hypercube, HCN(n,n), HFN(n,n). The results of embedding are that HCN(n,n), HFN(n,n) and Hypercube $Q_{2n}$ can be embedded into HFH($C_n,C_n$) with expansion $\frac{C^n}{2^{2n}}$ and dilation 2, 3, and 4, respectively. Also, HFH($C_n,C_n$) can be embedded into HFN(2n,2n) with dilation 1. These results mean so many developed algorithms in Hypercube, HCN(n,n), HFN(n,n) can be used efficiently in HFH($C_n,C_n$).

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.373-375
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• 2003

최근에 하이퍼큐브의 망비용을 개선한 상호연결망 하이퍼-스타가 제안되었다. 본 논문에서는 상호연결망 하이퍼-스타 HS(2n,n)가 제안된 매핑 알고리즘에 의해 노드 대칭임을 보인다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.61-63
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• 2004

최근에 하이퍼큐브의 망비용을 개선한 상호연결망 하이퍼-스타가 제안되었다. 본 논문에서는 삼진트리가 하이퍼-스타 연결망 HS(2n, n)에 연장율 1로 임베딩 가능함을 보인다.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.39.2-39.2
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• 2018

GW170817/GRB170817A establishes a double neutron star merger as the progenitor of a short gamma-ray burst, starting 1.7 s post-coalescence. GRB170817A represents prompt or continuous emission from a newly formed hyper-massive neutron star or black hole. We report on a deep search for broadband extended gravitational-wave emission in spectrograms up to 700 Hz of LIGO O2 data covering this event produced by butterfly filtering comprising a bank of templates of 0.5 s. A detailed discussion is given of signal-to-noise ratios in image analysis of spectrograms and confidence levels of candidate features. This new pipeline is realized by heterogeneous computing with modern graphics processor units (GPUs). (Based on van Putten, M.H.PM., 2017, PTEP, 093F01.)

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.418-420
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• 2003

최근에 하이퍼큐브의 망비용을 개선한 상호연결망 하이퍼-스타가 제안되었다. 본 논문에서는 상호연결 망 하이퍼-스타 HS(2n,n)의 평균거리가 (equation omitted)임을 보이고, 스패닝 트리를 이용한 일-대-다 방송 기법을 제안하고, 방송 수행 시간이 2n-1임을 보인다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.58-60
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• 2004

최근에 하이퍼큐브의 망비용을 개선한 하이퍼-스타 연결망이 제안되었다. 본 논문에서는 하이퍼-스타 연결망 HS(2n, n)의 container를 이용하여 k-wide diameter가 dist(u, v)＋4이하임과 HS(2n, n)의 고장지름이 D(HS(2n, n))＋2 이하임을 보인다.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.39.2-39.2
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• 2017

Over the last decade, deep studies of nearby galaxies have led to the discovery of vast stellar envelopes that are often rich in substructure. These components are naturally predicted in models of hierarchical galaxy assembly, and their observed properties place important constraints on the amount, nature, and history of satellite accretion. One of the most effective ways of mapping the peripheral regions of galaxies is through resolved star studies. Using wide-field cameras equipped to 8 m class telescopes, it has recently become possible to extend these studies to systems beyond the Local Group. Located at a distance of 3.6 Mpc, M81 is a prime target for wide-field mapping of its resolved stellar content. In this talk, we present the detailed results from our deep wide-field imaging survey of the M81 group with the Hyper Suprime-Cam (HSC), on the Subaru Telescope. We report on the analysis of the structures, stellar populations, and metallicities of old dwarf galaxies such as NGC3077, IKN, KDG061, as well as young stellar systems such as Arp's Loop and Holmberg IX. Several candidates for yet-undiscovered faint dwarf galaxies and young stellar clumps in the M81 group will also be introduced. The peculiar galaxy NGC3077 has been classified as the irregular galaxy. Okamoto et al. (2015, ApJ 809, L1) discovered an extended halo structure with S-shape elongated tails, obvious feature of tidal interaction. With a help of numerical simulation by Penarrubia et al. (2009, ApJ 698, 222), we will demonstrate that this tidal feature was formed during the latest close encounters between M81, M82, and NGC 3077, which induced star formation in tidally stripped gas far from the main bodies of galaxies. It is not clear whether the latest tidal interaction was the first close encounters of three galaxies. If NGC3077 is still surrounded by the dark matter halo, it implies that NGC3077 has undergone the first tidal stripping by larger companions. Kinematic studies of inter galactic globular clusters and planetary nebulae would tell us the past history of tidal interaction in this group of galaxies.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.41-43
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• 2019

Image-to-image 변환에서 인상적인 성능을 보이는 StarGAN 은 모델의 성능에 중요한 영향을 끼치는 adversarial weight, classification weight, reconstruction weight 라는 세가지 하이퍼파라미터의 결정을 전제로 하고 있다. 본 연구에서는 이 중 conditional GAN loss 인 adversarial loss 와 classification loss 를 대치할 수 있는 attribute loss를 제안함으로써, adversarial weight와 classification weight 를 최적화하는 데 걸리는 시간을 attribute weight 의 최적화에 걸리는 시간으로 대체하여 하이퍼파라미터 탐색에 걸리는 시간을 획기적으로 줄일 수 있게 하였다. 제안하는 attribute loss 는 각 특징당 GAN 을 만들 때 각 GAN 의 loss 의 합으로, 이 GAN 들은 hidden layer 를 공유하기 때문에 연산량의 증가를 거의 가져오지 않는다. 또한 reconstruction loss 를 단순화시켜 연산량을 줄인 simplified content loss 를 제안한다. StarGAN 의 reconstruction loss 는 generator 를 2 번 통과하지만 simplified content loss 는 1 번만 통과하기 때문에 연산량이 줄어든다. 또한 이미지 Framing 을 통해 배경의 왜곡을 방지하고, 양방향 성장을 통해 학습 속도를 향상시킨 아키텍쳐를 제안한다.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.225-230
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• 2017

The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z~1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field ($5.4deg^2$), using ~10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ~25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute significantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1< z <2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP field in 5 broad bands (g, r, i, z, and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate midIR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06a
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• pp.357-358
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• 2008

폴디드 하이퍼스타 FHS(2n,n)은 하이퍼큐브와 그의 변형된 그래프보다 망 비용이 개선된 상호연결망이다. 본 논문에서는 폴디드 하이퍼스타 FHS(n-1,k-1)와 FHS(n-1,k) 그래프를 연결하여 폴디드 하이퍼스타 FHS(n,k)를 생성하는 방법을 제시하였다(단, n=2k). 또한, 정규 연결망 형태인 폴디드 하이퍼스타 FHS(2n,n)의 노드연결도는 n+1이고, 최대고장허용도를 가짐을 보인다.