Exact Holography of Massive M2-brane Theories and Entanglement Entropy

Jang, Dongmin,Kim, Yoonbai,Kwon, O-Kab,Tolla, D. D.,Gwak, B.,Kang, G.,Kim, C.,Kim, H.-C.,Lee, C.-H.,Lee, J.,Lee, S.,Lee, W. EDP Sciences 2018 The European Physical Journal Conferences Vol.168 No.-

<P>We test the gauge/gravity duality between the <I>N</I> = 6 mass-deformed ABJM theory with U<I>k</I>(<I>N</I>) × U<I>-k</I>(<I>N</I>) gauge symmetry and the 11-dimensional supergravity on LLM geometries with <I>SO</I>(4)=ℤ<I>k</I> × <I>SO</I>(4)=ℤ<I>k</I> isometry. Our analysis is based on the evaluation of vacuum expectation values of chiral primary operators from the supersymmetric vacua of mass-deformed ABJM theory and from the implementation of Kaluza-Klein (KK) holography to the LLM geometries. We focus on the chiral primary operator (CPO) with conformal dimension Δ = 1. The non-vanishing vacuum expectation value (vev) implies the breaking of conformal symmetry. In that case, we show that the variation of the holographic entanglement entropy (HEE) from it’s value in the CFT, is related to the non-vanishing one-point function due to the relevant deformation as well as the source field. Applying Ryu Takayanagi’s HEE conjecture to the 4-dimensional gravity solutions, which are obtained from the KK reduction of the 11-dimensional LLM solutions, we calculate the variation of the HEE. We show how the vev and the value of the source field determine the HEE.</P>

Exact holography of the mass-deformed M2-brane theory

Jang, Dongmin,Kim, Yoonbai,Kwon, O-Kab,Tolla, D. D. Springer-Verlag 2017 European Physical Journal C Vol.77 No.5

<P>We test the holographic relation between the vacuum expectation values of gauge invariant operators in N = 6 U-k (N) x U-k (N) mass-deformed ABJM theory and the LLM geometries with Z(k) orbifold in 11-dimensional supergravity. To do so, we apply the Kaluza-Klein reduction to construct a 4-dimensional gravity theory and implement the holographic renormalization procedure. We obtain an exact holographic relation for the vacuum expectation values of the chiral primary operator with conformal dimension Delta = 1, which is given by < O-(Delta=1)> = N (3/2) f(Delta = 1), for large N and k = 1. Here the factor f(Delta) is independent of N. Our results involve an infinite number of exact dual relations for all possible supersymmetric Higgs vacua and so provide a non-trivial test of gauge/gravity duality away from the conformal fixed point. We extend our results to the case of k not equal 1 for LLM geometries represented by rectangular-shaped Young diagrams. We also discuss the exact mapping of the gauge/gravity at finite N for classical supersymmetric vacuum solutions in field theory side and corresponding classical solutions in gravity side.</P>

Pattern analysis for short and long-term traffic prediction: a case study of Daejeon

Dongmin Jang,Sungwon Park,Minki Kim,Seungkyu Ryu,Wonsu Kim 한국콘텐츠학회 2021 한국콘텐츠학회 ICCC 논문집 Vol.2021 No.12

Estuary classification method for considering climate change effects in South Korea

Jang, Dongmin,Hwang, Jin Hwan BioOne (Coastal Education and Research Foundation) 2013 JOURNAL OF COASTAL RESEARCH Vol.65 No.-

<P>Sea level rise attributed to climate change is expected to affect the estuaries of South Korea significantly. The seawater intrudes into the beds of river channels and into aquifers near the coastal zone, and such processes are expected to be magnified in the climate change regime. Further, flooding and erosion are expected to be intensified at the shorelines of rivers and in coastal zones. Such adverse effects are expected to occur, which will depend on the individual characteristics of different estuaries. Some of these characteristics include the volume of a tidal prism, the length of shoreline peripheral, and the bathymetries in the estuaries. Our present work modified the existing estuary classification systems to be more responsive to climate change; in particular, we have included the wave change impact. Many studies have proposed estuarine classifications recognizing the various features of each estuary. There are several ways to classify estuaries. First, estuaries can be classified with the Estuarine Circulation Classification (ECC) system. Second, Geomorphological Classification (GC) categorizes estuaries with the dominances among physical components. Third, Estuary Environment Classification (EEC) classifies with indices representing the physical processes and estuary shapes. However, these existing methods did not involve qualitative categorizations and also excluded the wave factor. They also did not include a category for the artificial estuaries, which are prevalent in Korea. Therefore, efficiently constructing a comprehensive response plan for the climate change based on these existing classification systems was not possible. Thus, a new quantitative method including the wave index and considering the artificial estuary is proposed here that can be utilized in a response to climate change.</P>

Mass-deformed ABJM theory and LLM geometries: exact holography

Jang, Dongmin,Kim, Yoonbai,Kwon, O-Kab,Tolla, D.D. Springer-Verlag 2017 Journal of high energy physics Vol.2017 No.4

Downscaled Numerical Modelling to Study the Climate Change Effects on the Estuarine Stratification

Jang, Dongmin,Hwang, Jin H.,Nguyen, Thao T.H. BioOne (Coastal Education and Research Foundation) 2016 JOURNAL OF COASTAL RESEARCH Vol.75 No.special

Fire Dynamics Simulator 기반 실시간 화재 시뮬레이션 소프트웨어 구현

장동민(Dongmin Jang),송요한(Yohan Song),김정우(Jung Woo Kim) 한국화재소방학회 2022 한국화재소방학회 학술대회 논문집 Vol.2022 No.추계

화재 대응력 향상을 위한 훈련 소프트웨어는 건축물 및 공간에서 확산되는 화재 및 연기에 대한 화재 및 유체 흐름을 실제와 유사하게 구현해야 훈련 효과를 향상할 수 있다. 본 논문에서는 실제와 유사한 화재 및 유체 흐름을 제공하기 위해 FDS(Fire Dynamics Simulator) 데이터를 이용한다. FDS는 화재 유체 흐름에 대한 CFD(Computational Fluid Dynamics) 모델로 화재로 인한 연기와 열전달을 3차원으로 해석한다. 하지만, FDS의 계산 과정은 실시간으로 처리하기에는 많은 계산 시간과 대용량 데이터를 요구한다. 따라서, 게임 엔진에 실시간으로 적용하기 위한 FDS 데이터 처리 및 가시화 방법이 필요하다. FDS 데이터를 게임 엔진에 적용하기 위해 전처리 과정을 거치며, 공간, 위치, 화재 데이터로 구분하여 처리하였다. 공간 데이터는 모델링 처리, 감지기 및 스프링클러 구성, 구역별 토폴로지 공간으로 구성된다. 위치 및 화재 데이터는 온도, 열감지기, 연기감지기, 스프링클러, 일산화탄소, 산소, 가시성에 대한 열량 데이터를 시간, 위치에 따라 가중치에 의한 속성에 의해 단계화되어 전처리된다. 상용 Unity 3D 게임 엔진을 이용하여 화재 및 연기의 파티클을 생성하여 화재 및 연기를 렌더링하였으며, 물리적 특성으로 연기의 흐름을 표현하기 위해 Fluvio 모듈을 이펙트 시스템에 적용하여 유체 처리하였다. 전처리된 화재 데이터는 시간에 따라 화재, 연기, 열감지기, 연기감지기, 스프링클러, 공기, 가시성으로 구분되어 시뮬레이션 된다. 화재, 연기, 가시성 시뮬레이션은 화재, 연기를 사용자에게 가시화하며, 실제 소방시설 동작 및 피해 계산은 열감지기, 연기감지기, 스프링클러, 공기 시뮬레이션하여 처리된다. 주요 결과로서, 게임 엔진에 FDS 기반 화재 시뮬레이션을 구현하여 실시간으로 동작함을 확인하였으며, 화재 시뮬레이션 시스템 설계 및 FDS 데이터 전처리 기술을 제안한다. 앞으로 전처리 기술 개선을 통해 FDS 기반 실시간 시뮬레이션 기술에 기여하고자 한다.

국내 OEM/ODM 화장품 제조기업의 생산계획 및 효율화를 위한 분산형 MRP시스템 개발

장동민(Dongmin Jang),신문수(Moonsoo Shin) 한국산업경영시스템학회 2020 한국산업경영시스템학회지 Vol.43 No.4

Up to date cosmetic OEM/ODM (original equipment manufacturing/original development manufacturing) industry receives attention as a future growth engine due to steady growth. However, because of limited research and development capability, many companies have employed commercial management platforms specialized for large-sized companies; thus, overall system effectiveness and efficiency is low. Especially, MRP (material requirement planning) system introduced originally in 1970s is employed to calculate the requirement of the parts. However, dynamic nature of production lead time usually results in incorrect requirements. In addition, its algorithm does not consider the capability of the production resources. Also, because the commercial MRP system calculates all subcomponent for fixed period, the more goods have subcomponent, the slower calculation is. Therefore, conventional MRP system cannot respond complicated situation in time. In this study, we will suggest a new method that can respond to complicated situations resulting from short lead time and urgent production order in Korean cosmetic market. In particular, a distributed MRP system is proposed, that consists of multi-functional and operational modules, based on the characteristic of the BOM (bill of material). The distributed MRP system divides components (i.e. products and parts) into several fields and decrease the problem size; thus, we can respond to dynamically changed data any time. Through this solution, we can order components quickly, adjust schedules and planned quantity, and manage stocks reasonably. In addition, a prototype of the distributed MRP system is presented in this paper, in which ERP (enterprise resource planning) sever data is associated with an excel spreadsheet via MSsql. System user interface is implemented by a VBA (visual basic for applications) tool. According to a case study, response rate for delivery and planning achievement rate were enhanced about 20%, and inventory turnover was also decreased. Consequently, the proposed system improves overall profit.

하천주변 식생군락 이미지 분석기법을 이용한 제방안정성 분석 연구

장동민(Dongmin Jang),박성원(Sungwon Park),김원수(Wonsu Kim) 한국콘텐츠학회 2022 한국콘텐츠학회 종합학술대회 논문집 Vol.2022 No.7

사용자 시점 기반 360 영상을 위한 렌더러 구현

장동민(Dongmin Jang),손장우(Jang-Woo Son),정종범(JongBeom Jeong),류은석(Eun-Seok Ryu) 한국방송·미디어공학회 2018 방송공학회논문지 Vol.23 No.6

In this paper, we implement viewport dependent tile partitioning for high quality 360 video transmission and rendering method to present a HMD (Head Mounted Display) screen for 360 video quality evaluation. As a method for high-quality video transmission based on a user’s viewport, this paper introduces MCTS (Motion Constrained Tile Sets) technique for solving the motion reference problem and EIS (Extraction Information Sets) SEI including pre-configured tile information, and extractor that extracts tiles. In addition, it explains tile extraction method based on user’s viewport and implementation contents of the method of expressing on an HMD. Therefore, if 360 video is transferred by the proposed implementation which only transfers video from the user viewport area, it is possible to express higher quality video with lower bandwidth while avoiding unnecessary image transmission.