• Title/Summary/Keyword: Multi-Level

Search Result 4,791, Processing Time 0.037 seconds

Study on the Characteristics of Gas Hydrate Layers Distributed in the Southern Ulleung Basin, the East Sea (동해 울릉분지 남부해역에 분포하는 가스 하이드레이트층의 특성 연구)

  • Huh Sik;Yoo Hai-Soo;Kim Han-Joon;Han Sang-Joon;Lee Yong-Kuk
    • The Korean Journal of Petroleum Geology
    • /
    • v.10 no.1_2 s.11
    • /
    • pp.18-22
    • /
    • 2004
  • To identify and interpret the distribution and the characteristics of the gas hydrate layers in the Ulleung Basin, we have surveyed and gathered the multi-channel seismic data, Chirp sub-bottom profiler, SeaBeam and 12 m piston core samples since 1996. In previous works, high-resolution seismic profiles showed acoustic anomalies such as acoustic void, acoustic turbidity and pock mark which indicate the presence of gas-charged sediments. The patterns of horizontal degassing cracks originated from free methane expansion is the strong indicator of shallow gas-charged sediments in the core samples. The observation of submarine slides and slumps from destabilizing the sediments in the southern part of the Ulleung Basin may also point out that the gas had been released from gas hydrate dissociation during lowstand of sea level. The multi-channel seismic data show BSR, blanking and phase reversal. The gas hydrate layers above which large-scale shallow gases are distributed exist at the depth of about 200 m from the sea-floor with water depth of 2,100 m. From the interpretation of seismic sections in the southern Ulleung Basin, gas hydrate layers occur in the Pleistocene-Holocene sediments. These gas-charged sediments, acoustic anomalies and BSR may be all related to the existence of gas hydrate layers in the study area.

  • PDF

H*-tree/H*-cubing-cubing: Improved Data Cube Structure and Cubing Method for OLAP on Data Stream (H*-tree/H*-cubing: 데이터 스트림의 OLAP를 위한 향상된 데이터 큐브 구조 및 큐빙 기법)

  • Chen, Xiangrui;Li, Yan;Lee, Dong-Wook;Kim, Gyoung-Bae;Bae, Hae-Young
    • The KIPS Transactions:PartD
    • /
    • v.16D no.4
    • /
    • pp.475-486
    • /
    • 2009
  • Data cube plays an important role in multi-dimensional, multi-level data analysis. Meeting on-line analysis requirements of data stream, several cube structures have been proposed for OLAP on data stream, such as stream cube, flowcube, S-cube. Since it is costly to construct data cube and execute ad-hoc OLAP queries, more research works should be done considering efficient data structure, query method and algorithms. Stream cube uses H-cubing to compute selected cuboids and store the computed cells in an H-tree, which form the cuboids along popular-path. However, the H-tree layoutis disorderly and H-cubing method relies too much on popular path.In this paper, first, we propose $H^*$-tree, an improved data structure, which makes the retrieval operation in tree structure more efficient. Second, we propose an improved cubing method, $H^*$-cubing, with respect to computing the cuboids that cannot be retrieved along popular-path when an ad-hoc OLAP query is executed. $H^*$-tree construction and $H^*$-cubing algorithms are given. Performance study turns out that during the construction step, $H^*$-tree outperforms H-tree with a more desirable trade-off between time and memory usage, and $H^*$-cubing is better adapted to ad-hoc OLAP querieswith respect to the factors such as time and memory space.

A Bio-Edutainment System to Virus-Vaccine Discovery based on Collaborative Molecular in Real-Time with VR

  • Park, Sung-Jun
    • Journal of the Korea Society of Computer and Information
    • /
    • v.25 no.6
    • /
    • pp.109-117
    • /
    • 2020
  • An edutainment system aims to help learners to recognize problems effectively, grasp and classify important information needed to solve the problems and convey the contents of what they have learned. Edutainment contents can be usefully applied to education and training in the both scientific and industrial areas. Our present work proposes an edutainment system that can be applied to a drug discovery process including virtual screening by using intuitive multi-modal interfaces. In this system, a stereoscopic monitor is used to make three-dimensional (3D) macro-molecular images, with supporting multi-modal interfaces to manipulate 3D models of molecular structures effectively. In this paper, our system can easily solve a docking simulation function, which is one of important virtual drug screening methods, by applying gaming factors. The level-up concept is implemented to realize a bio-game approach, in which the gaming factor depends on number of objects and users. The quality of the proposed system is evaluated with performance comparison in terms of a finishing time of a drug docking process to screen new inhibitors against target proteins of human immunodeficiency virus (HIV) in an e-drug discovery process.

Back-scattering Characteristic Analysis for SAR Calibration Site (SAR 검보정 Site 구축을 위한 후방 산란 특성 분석)

  • Lee, Taeseung;Yang, Dochul
    • Korean Journal of Remote Sensing
    • /
    • v.37 no.2
    • /
    • pp.305-319
    • /
    • 2021
  • The overseas calibration sites such as Mongolia used for Korea Multi-purpose Satellite (KOMPSAT-5 or K5), have a disadvantage in that maintenance and repair costs are high and immediate response is difficult when an unexpected problem occurs. Accordingly, the necessity of establishing a domestic SAR calibration site was suggested, but the progress of related research is insignificant. In this paper, we investigated what conditions should be satisfied in terms of backscattering characteristics to construct a site for SAR satellite image quality evaluation and calibration. First of all, it was selected first by applying general indicators such as accessibility and availability among places recommended as satellite image calibration candidate sitesin Korea. Next, three places, site A (Goheung-gun, Jeollanam-do), site B (Jeonju-si, Jeollabuk-do), and site C (Daedeok Research Complex, Daejeon), were selected as the final candidates because they are relatively wide and easy to install AT or CR. Site A, located in Goheung-gun, Jeollanam-do, was best considered in terms of slope measurements, minimum site area to obtain ISLR, uniformity of DN values and backscatter coefficients, interference by strong reflectors, and backscatter clutter level.

A Study on Economic Effects of NAMA Negotiations in the WTO on Automotive Industry of the World (WTO 비농산물협상이 전세계 자동차산업에 미치는 영향에 관한 연구)

  • Ko, Jong-Hwan
    • International Area Studies Review
    • /
    • v.15 no.3
    • /
    • pp.95-126
    • /
    • 2011
  • The objective of this study is to quantify the potential economic effects of Non-Agricultural Market Access (NAMA) negotiations of the WTO on automotive industry of the world using a multi-region, multi-sector Computable General Equilibrium (CGE) model with 21 countries/regions and 22 sectors. According to the December 2008 NAMA modalities text, issued by the chair of the negotiation on NAMA, three different scenarios of tariff liberalization of NAMA are conducted on the basis of the Swiss formula with a coefficient of 8 for developed members and 20 for developing (scenario 1), with a coefficient of 8 for developed members and 22 for developing (scenario 2) and with a coefficient of 8 for developed members and 25 for developing (scenario 3). Simulation results show potential economic effects at the macroeconomic and microeconomic level of 21 countries concerned. In particular, Korea is to be one of the winners of tariff liberalization of NAMA in the WTO and Korean automotive industry is to benefit from it to a large extent in terms of its output, domestic sales, exports and trade balance, which implies that Korea needs to actively engage in NAMA negotiations of the WTO.

The Effect of Department of Emergency Medical Service Students' Knowledge and Attitudes toward Tuberculosis Infection Prevention Behaviors (응급구조학과 학생들의 결핵에 대한 지식 및 태도가 결핵감염 예방행위에 미치는 영향)

  • Moon, Sung-Mo;Kim, Duk-Won
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.2
    • /
    • pp.259-266
    • /
    • 2019
  • This study aimed to identify factors that had an influence on preventive behaviors of Emergency Medical Service students against tuberculosis to promote their preventive behavior. The subjects of the study were 314 students studying emergency medical service from one 4-year college and two 3-year colleges in Jeollabukdo and they were researched with the use of a questionnaire from June 25, to July 6, 2018. For a statistical analysis of the data obtained, this study used SPSS 18.0 and conducted a t-test, an ANOVA, a Pearson's correlation coefficient and a multi-regression test to analyze the data. Pearson's correlation coefficient analysis showed that the preventive behavior levels was significantly correlated with knowledge of tuberculosis (r = 0.268, p <0.001) and attitude (r = 0.394, p<0.001). As results of the multi-regression test, the higher the knowledge of tuberculosis(${\beta}=0.152$, p<0.001) and the higher the attitude(${\beta}=0.052$, p<0.001), the higher the preventive behavior levels. In addition, Students who have experienced tuberculosis in their own or relative's relatives have a high level of prevention behavior(${\beta}=-0.186$, p=0.001). Therefore, it is suggested that organized and consistent education programs to promote knowledge on tuberculosis, change negative perception on it and improve preventive behavior levels should be developed and provided.

SOURCE-FREQUENCY PHASE-REFERENCING OBSERVATION OF AGNS WITH KAVA USING SIMULTANEOUS DUAL-FREQUENCY RECEIVING

  • Zhao, Guang-Yao;Jung, Taehyun;Sohn, Bong Won;Kino, Motoki;Honma, Mareki;Dodson, Richard;Rioja, Maria;Han, Seog-Tae;Shibata, Katsunori;Byun, Do-Young;Akiyama, Kazunori;Algaba, Juan-Carlos;An, Tao;Cheng, Xiaopeng;Cho, Ilje;Cui, Yuzhu;Hada, Kazuhiro;Hodgson, Jeffrey A.;Jiang, Wu;Lee, Jee Won;Lee, Jeong Ae;Niinuma, Kotaro;Park, Jong-Ho;Ro, Hyunwook;Sawada-Satoh, Satoko;Shen, Zhi-Qiang;Tazaki, Fumie;Trippe, Sascha;Wajima, Kiyoaki;Zhang, Yingkang
    • Journal of The Korean Astronomical Society
    • /
    • v.52 no.1
    • /
    • pp.23-30
    • /
    • 2019
  • The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interferometry (VLBI) facilities all over the globe start to implement compatible optics systems. Simultaneous dual/multi-frequency VLBI observations at mm wavelengths with international baselines are thus possible. In this paper, we present the results from the first successful simultaneous 22/43 GHz dual-frequency observation with KaVA(KVN and VERA array), including images and astrometric results. Our analysis shows that the newly implemented simultaneous receiving system has brought a significant extension of the coherence time of the 43 GHz visibility phases along the international baselines. The astrometric results obtained with KaVA are consistent with those obtained with the independent analysis of the KVN data. Our results thus confirm the good performance of the simultaneous receiving systems for the nonKVN stations. Future simultaneous observations with more global stations bring even higher sensitivity and micro-arcsecond level astrometric measurements of the targets.

A Study of Evaluating Streetscape Green Environments to Improve Urban Street Green Spaces - A Case Study of Jeonju City - (도시가로녹지의 개선을 위한 녹화환경평가 연구 -전주시를 대상으로-)

  • Jeong, Moon-Sun;Lim, Hyun-Jeong
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.22 no.3
    • /
    • pp.55-71
    • /
    • 2019
  • The purpose of this study is to propose an evaluation method to assess green environments of streetscapes to improve urban street green spaces in Jeonju City. Through a rapid assessment of urban street green spaces, we suggest an objective basis for expanding street green space as well as for adopting sustainable maintenance and improvement measures. We choose 12 sections of streetscapes (roads and sidewalks) to investigate existing street conditions which have more than four lanes and function as major road axes. Six large roads and six medium roads of Jeonju City center area are investigated as pilot assessment study sites. Site inventory checklists consist of environmental characteristics of streetscape, street tree status, and planting condition evaluation. Environmental characteristics of streetscapes are composed of physical and neighborhood factors. For instance, items for physical factors are types and width of road/sidewalks, paving materials, tree protection materials, and green strip. And surrounding landuse is a neighborhood factor. Assessment items for street tree status are street plant names (tree/shrubs/ground cover), size, and planting intervals. Planting condition evaluation items are tree shape, damage, canopy density, and planting types with existence of adjacent green space. Evaluation results are classified into three levels such as A(maintain or repair), B(greening enhancement), and C(structural improvement). In case of grade A, streetscapes have enough sidewalk width for maintaining green strip and a multi-layered planting(in large road only) with fairly good growing conditions of street trees. For grade B and C, streetscapes have a moderate level of sidewalk width with a single street tree planting. In addition, street tree growing conditions are appeared poor so that green enhancement or maintenance measures are needed. For median, only grade B and C are found as its planting growing foundations are very limited in space. As a result, acquiring enough sidewalk space is essential to enhance ecological quality of urban street green. Especially, it is necessary to have green strip with reasonable widths for plant growing conditions in sidewalks. In addition, we need to consider native species with multi-layer plant compositions while designing street green.

Quantitative Analysis of Snow Particles Using a Multi-Angle Snowflake Camera in the Yeongdong Region (영동지역에서 눈결정 카메라를 활용한 눈결정의 정량 분석)

  • Kim, Su-Hyun;Ko, Dae-Hong;Seong, Dae-Kyung;Eun, Seung-Hee;Kim, Byung-Gon;Kim, Baek-Jo;Park, Chang-Geun;Cha, Ju-Wan
    • Atmosphere
    • /
    • v.29 no.3
    • /
    • pp.311-324
    • /
    • 2019
  • We employed a Multi-Angle Snowflake Camera (MASC) to quantitatively analyze snow particles at the ground level in the Yeongdong region of Korea. The MASC captures high-resolution photographs of hydrometeors from three angles and simultaneously measures fallspeed. Based on snowflake images of the several episodes in 2017 and 2018, we derived statistics of size, aspect ratio, orientation, complexity, and fallspeed of snow crystals, which generally showed similar characteristics to the previous studies in other regions of the world. Dominant snow crystal habits of January 22, 2018 generated by northerly were melted aggregates when 850 hPa temperature was about $-6{\sim}-8^{\circ}C$. Average fallspeed of snow crystals was $1.0m\;s^{-1}$ though its size gradually increased as temperature decreased. Another snowfall event (March 8, 2018) was driven by the baroclinic instability as accompanied with a deep trough. Snow crystal habits were largely rimed aggregates (complexity ~1.8) and melting particles of dark images. Meanwhile, in the extreme snowfall event whose snow rate was greater than $10cm\;hr^{-1}$ on January 20, 2017, main snow crystals appeared to be heavily rimed particles with relatively smaller size when convective clouds developed vertically up to 9 km in association with tropopause folding. MASC also could successfully measure a decrease in snow crystal size and an increase in riming degree after AgI seeding at Daegwallyeong on March 14, 2017.

The development of the 2020 Dietary Reference Intakes for Korean population: Lessons and challenges (2020 한국인 영양소 섭취기준 제·개정: 교훈과 도전)

  • Kwon, Oran;Kim, Hyesook;Kim, Jeongseon;Hwang, Ji-Yun;Lee, Jounghee;Yoon, Mi Ock
    • Journal of Nutrition and Health
    • /
    • v.54 no.5
    • /
    • pp.425-434
    • /
    • 2021
  • The discovery of the relationship between nutrients and deficiency diseases during the 100 years from the mid-1800s to the mid-1900s was a breakthrough that led to advances in the study of nutrition. The Recommended Dietary Allowances (RDA) were created as a quantitative standard for avoiding diseases caused by nutrient deficiency. In addition, a reductionism paradigm has become generally accepted among nutrition scholars in health and disease, which focused on the properties of individual nutrients, content in foods, cellular levels, and mechanisms of action. The reductionist paradigm worked very well for the prevention and treatment of malnutrition diseases. However, as the incidence of nutrient deficiencies decreased and that of chronic diseases increased, the nutrition goals have been changed to secure safe and adequate nutrient intake and to reduce chronic disease risks. Accordingly, Dietary Reference Intakes (DRIs), a set of nutrient-based reference values, were designed to replace the RDA. The revised Korean DRIs were published for 40 nutrients in 2020. However, there is still room for improvement in the reference intake levels targeted at reducing the risk of chronic disease. The reductionist approach can no longer be practical because chronic diseases are related to the interactions between multi-components in the foods and multi-targets in the body. Therefore, a second innovative leap is needed following the nutrition development breakthrough made over 100 years ago. To this end, the nutrition paradigm must evolve from reductionism to a holism approach. Cutting-edge scientific technologies, such as metabolomics, transcriptomics, microbiomics, and bioinformatics, should also be acceptable in nutrition science based on the knowledge gained from basic nutrition studies.