• Title/Summary/Keyword: knots

Search Result 430, Processing Time 0.032 seconds

The Evolution and Structural Characteristics of Scaffolding Constructions in Macao Area from Historical Documents and Visual Materials (문헌 및 도상(圖像) 사료를 통해 본 마카오 '붕식(棚式)' 건축의 연원(淵源)과 구조 형식)

  • Hong, Shu-ying;Han, Dong-Soo
    • Journal of architectural history
    • /
    • v.32 no.1
    • /
    • pp.7-20
    • /
    • 2023
  • The construction method of scaffolding structures is different from Mortise and Tenon and bucket arch structure of traditional large woodwork. It forms an independent construction system-fixing nodes with knots, a large number of diagonal braces are used to fix shelves and the structures mostly contain X-shape and triangular shape details. Simple ones include stalls, sheds, rain sheds, altars, lamp racks etc. But the scaffolding with larger scale and more complicated structure are modeled on archways, theatres and other buildings which are used in commercial and festival activities. At present, Macao, Hong Kong, Guangdong, Sichuan, Shanxi and other places in China have retained the custom of using scaffolding structures in important festival activities, but their uses, techniques and building types are slightly different from place to place. Due to building and demolishing at any time, the construction and service cycle is short. As a result, there are almost no physical objects left. We can only deduce the use and technical characteristics of ancient scaffolding skills through the colorful building styles that have been preserved with folk activities in various parts of China, the craftsmanship handed down from generation to generation by the scaffolding guild and artisans, and the description of cultural and historical materials and the mutual corroboration of visual materials.

A GMOS/IFU Spectroscopic Mapping of Jellyfish Galaxies in Extremely Massive Galaxy Clusters

  • Lee, Jeong Hwan;Lee, Myung Gyoon;Kang, Jisu;Cho, Brian S.;Mun, Jae Yeon
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.45 no.1
    • /
    • pp.32.3-33
    • /
    • 2020
  • Jellyfish galaxies show spectacular features such as star-forming knots and tails due to strong ram-pressure stripping in galaxy clusters. Thus, jellyfish galaxies are very useful targets to investigate the effects of ram-pressure stripping on the star formation activity in galaxies. Integral field spectroscopy (IFS) studies are the best way to study star formation in jellyfish galaxies, but they have been limited to those in low-mass galaxy clusters until now. In this study, we present a Gemini GMOS/IFU study of three jellyfish galaxies in very massive clusters (M_200 > 10^15 Mo). The host clusters (Abell 2744, MACSJ0916.1-0023, and MACSJ1752.0+4440) are X-ray luminous and dynamically unstable, suggesting that ram-pressure stripping in these clusters is much stronger than in low-mass clusters. We present preliminary results of star formation rates, kinematics, dynamical states, and ionization mechanisms of our sample galaxies and discuss how ram-pressure stripping relates with the star formation activity of jellyfish galaxies in massive clusters.

  • PDF

Teaching-learning-based strategy to retrofit neural computing toward pan evaporation analysis

  • Rana Muhammad Adnan Ikram;Imran Khan;Hossein Moayedi;Loke Kok Foong;Binh Nguyen Le
    • Smart Structures and Systems
    • /
    • v.32 no.1
    • /
    • pp.37-47
    • /
    • 2023
  • Indirect determination of pan evaporation (PE) has been highly regarded, due to the advantages of intelligent models employed for this objective. This work pursues improving the reliability of a popular intelligent model, namely multi-layer perceptron (MLP) through surmounting its computational knots. Available climatic data of Fresno weather station (California, USA) is used for this study. In the first step, testing several most common trainers of the MLP revealed the superiority of the Levenberg-Marquardt (LM) algorithm. It, therefore, is considered as the classical training approach. Next, the optimum configurations of two metaheuristic algorithms, namely cuttlefish optimization algorithm (CFOA) and teaching-learning-based optimization (TLBO) are incorporated to optimally train the MLP. In these two models, the LM is replaced with metaheuristic strategies. Overall, the results demonstrated the high competency of the MLP (correlations above 0.997) in the presence of all three strategies. It was also observed that the TLBO enhances the learning and prediction accuracy of the classical MLP (by nearly 7.7% and 9.2%, respectively), while the CFOA performed weaker than LM. Moreover, a comparison between the efficiency of the used metaheuristic optimizers showed that the TLBO is a more time-effective technique for predicting the PE. Hence, it can serve as a promising approach for indirect PE analysis.

Mapping the Star Formation Activity of Five Jellyfish Galaxies in Massive Galaxy Clusters with GMOS/IFU

  • Lee, Jeong Hwan;Lee, Myung Gyoon;Mun, Jae Yeon
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.46 no.2
    • /
    • pp.43.2-43.2
    • /
    • 2021
  • Ram-pressure stripping (RPS) is known as the main driver of quenching the star formation (SF) activity in cluster galaxies. However, galaxies undergoing RPS in galaxy clusters often show blue star-forming knots in their disturbed disks and tails. The existence of these "jellyfish galaxies" implies that RPS can temporarily boost the SF activity of cluster galaxies. Thus, jellyfish galaxies are very unique and interesting targets to study the influence of RPS on their SF activity, in particular with integral field spectroscopy (IFS). While there have been many IFS studies of jellyfish galaxies in low-mass clusters (e.g., the GASP survey), IFS studies of those in massive clusters have been lacking. We present an IFS study of five jellyfish galaxies in massive clusters at intermediate redshifts using the Gemini GMOS/IFU. Their star formation rates (SFRs) are estimated to be up to 15 Mo/yr in the tails and 50 Mo/yr in the disks. These SFRs are by a factor of 10 higher than those of star-forming galaxies on the main sequence in the M*-SFR relation at similar redshifts. Our results suggest that the SF activity of jellyfish galaxies tends to be more enhanced in massive clusters than in low-mass clusters. This implies that strong RPS in massive clusters can trigger strong starbursts.

  • PDF

A GMOS/IFU Study of Enhanced Star Formation Activity of Jellyfish Galaxies in Massive Galaxy Clusters

  • Lee, Jeong Hwan;Lee, Myung Gyoon;Kang, Jisu;Cho, Brian S.;Mun, Jae Yeon
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.46 no.1
    • /
    • pp.55.1-55.1
    • /
    • 2021
  • Ram-pressure stripping (RPS) is known as a typical mechanism of quenching star formation (SF) of galaxies orbiting in clusters, but it can also boost the SF activity within a short period of time. Jellyfish galaxies, with eye-catching blue tails and knots, are such starburst galaxies undergoing strong RPS in galaxy clusters. Thus, they are very useful targets to understand their SF activity in relation to RPS. We study the SF activity of three jellyfish galaxies in massive clusters at z=0.3-0.4 (MACSJ1752-JFG2, MACSJ0916-JFG1, and A2744-F0083) with Gemini GMOS/IFU and compare our results to those of jellyfish galaxies in low-mass clusters. We obtain total star formation rates (SFRs) of up to 60 Mo/yr and SFRs in the tails of up to 15 Mo/yr, which are much higher than those of jellyfish galaxies in low-mass clusters with the median SFRs of 1.1 Mo/yr in total and 0.03 Mo/yr in tails. In addition, these SFRs are also significantly higher than the SF main sequence of galaxies at the redshifts of the three jellyfish galaxies. This implies that their SF activity is much more enhanced compared to jellyfish galaxies in low-mass clusters due to extreme RPS in massive clusters.

  • PDF

A Study on the Impact of Slow Steaming on Containership Operations under the Carbon Intensity Indicator Regulation

  • Daesik Seo;Youngran Shin
    • Journal of Navigation and Port Research
    • /
    • v.48 no.2
    • /
    • pp.97-103
    • /
    • 2024
  • As there is growing concern about the environmental impact of greenhouse gas emissions from ships, the International Maritime Organization (IMO) has introduced several regulations targeting reductions in carbon dioxide emissions of 50% by 2050. This study pays particular attention to the carbon intensity indicator (CII) and investigates the impact of slow steaming, one of the short-term measures in the regulation, on containership operations. To this end, a dataset of 8 containerships with various ages and sizes was collected. Based on operation data in 2021, the CII ratings of the containerships were estimated in the business-as-usual scenario for the 2023-2030 period. Then, the speed reductions required to keep the minimum CII rating were calculated for individual containerships. Finally, working day losses resulting from the speed reductions were calculated. The findings in this study were threefold. First, it was found that containerships will undergo degradation in the CII rating every 3 or 4 years without slow steaming. Second, a speed reduction of 2 knots between 2023 and 2030 is required to keep the minimum CII rating. Finally, speed reductions result in the loss of as many as 6 or 7 working days per year.

A Study on The Layered Look by Applying Characteristics of Men's Baeja from The Joseon Dynasty (조선시대 남자 배자를 응용한 레이어드 룩 스타일 디자인 연구)

  • Yeom, Jeong-Soon;Kim, Eun Jung
    • Journal of the Korean Home Economics Association
    • /
    • v.50 no.6
    • /
    • pp.55-64
    • /
    • 2012
  • This study aims to reinterpret formative elements of Baeja, by applying them to the design of modern clothing. The main objective of the studying Baeja is to propose unique layered look items that can be readily put together for various weather conditions and occasions, be easily wearable and bring out unique individualities. After carefully studying Baeja from Joseon dynasty, flexible and practical layered-look items are designed. The following are the conclusions drawn from the work. First, it is possible to apply Baeja elements, such as the silhouette, traditional materials, and colors, to modern clothes, for a layered-look. Second, Baeja characteristics have a profound potential for a modern layered-look design, in that it is sleeveless, its length is long at the front and short at the back, and it comes with slits on both sides and a wide belt. The items inspired by such characteristic can easily be worn over and draped around daily clothes, according to weather conditions and occasions. Third, many decorative elements of Baeja, including detailed ornamental method, knots, patchworks, and string decorations create a unique and traditional image in modern clothes. Ribbonswhich can adjust the width of clothes are both practical and decorative. A reversible jacket is created by utilizing the same traditional sewing method for both inner and outer fabrics. One item can be worn in different styles, which increases practicality. Fourth, traditional and modern materials go well together. Such methods can create an item with both modern sensibility and traditional chic.

On the Structural Analysis Using the Isogeometry Analysis Approach (등기하 해석법을 이용한 구조해석)

  • Lee, Joo-Sung;Chang, Kyoung-Sik;Roh, Myoung-Il
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.24 no.1
    • /
    • pp.55-60
    • /
    • 2011
  • In the present work, isogeometric analysis in linear elasticity problem is conducted using the basis functions from NURBS. The objectives of isogeometric analysis introduced is to integrate both geometric modeling(CAD) and computational analysis(CAE), and this can be accomplished from direct usage of geometric modeling by NURBS as the computational mesh. The merit of the isogeometry analysis is that NURBS surface are able to represent exact geometry from the control points and knot vectors, and also subsequent refinement is relatively simple relatively. In order to verify the computer codes developed in this study, it has been applied to two structural models of which geometry are simple ; 1) circular cylinder subjected to the constant internal pressure loading, 2) square plate with circular hole at center subjected to uniform tension. The exact solutions of these two models are available. Convergence of the approximate solutions by the present code for the isogeometry analysis are investigated by mesh refinement with inserting knots (h-refinement) and by mesh refinement with order elevation of the basis functions (p-refinement).

Measurement of Maneuverability in the Restricted Area by Numerical Model Ship (수치 모형선에 의한 제한수역에서의 조종성능 측정)

  • Park, Byung-Soo;Kim, Jong-Hwa;Kim, Cheog-Su
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.15 no.4
    • /
    • pp.363-367
    • /
    • 2009
  • The ship maneuverability is changed by the effects of the bank cushion and the squat in the restricted water area. It is difficult to test the ship maneuverability by the real ship in the restricted water area because of ship's safety. In this study, a numerical model ship was used to simulate the ship's motion and to get information about the bank cushion and the squat in the restricted water area. The less apart from the quay the ship ran, the more ship's heading changed. The greatest change of ship's heading was $22.37^{\circ}$ when a ratio of the length between ship and quay to ship's breadh(=D/B) was 0.2. The squat of the ship was greater in shallower water and at faster speed. The greatest squat was 0.29m when a ratio of water depth to ship's draft(H/d) was 1.25 and ship's speed was 8 knots, the reduced speed was found to be the most important factor in the shallow water area for safety of the ship.

  • PDF

Molecular Hydrogen Outflow in Infrared Dark Cloud Core MSXDC G53.11+00.05

  • Kim, Hyun-Jeong;Koo, Bon-Chul;Pyo, Tae-Soo;Davis, Christopher J.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.2
    • /
    • pp.41.4-42
    • /
    • 2015
  • Outflows and jets from young stellar objects (YSOs) are prominent observational phenomena in star formation process. Indicating currently ongoing star formation and directly tracing mass accretion, they provide clues about the accretion processes and accretion history of YSOs. While outflows of low-mass YSOs are commonly observed and well studied, such studies for high-mass YSOs have been so far rather limited owing to their large distances and high visual extinction. Recently, we have found a number of molecular hydrogen (H2 1-0 S(1) at 2.12 micron) outflows in the long, filamentary infrared dark cloud (IRDC) G53.2 located at 1.7 kpc from UWISH2, the unbiased, narrow-band imaging survey centered at 2.12 micron using WFCAM/UKIRT. In IRDC G53.2 which is an active star-forming region with ~300 YSOs, H2 outflows are ubiquitously distributed around YSOs along dark filaments. In this study, we present the most prominent H2 outflow among them identified in one of the IRDC cores MSXDC G53.11+00.05. The outflow shows a remarkable bipolar morphology and has complex structures with several flows and knots. The outflow size of ~1 pc and H2 luminosity about ~1.2 Lsol as well as spectral energy distributions of the Class I YSOs at the center suggest that the outflow is likely associated with a high-mass YSO. We report the physical properties of H2 outflow and characteristics of central YSOs that show variability between several years using the H2 and [Fe II] images obtained from UWISH2, UWIFE and Subaru/IRCS+AO188 observations. Based on the results, we discuss the possible origin of the outflow and accretion processes in terms of massive star formation occurring in IRDC core.

  • PDF