• Title/Summary/Keyword: simplified model

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Review on Discontinuum-based Coupled Hydro-Mechanical Analyses for Modelling a Deep Geological Repository for High-Level Radioactive Waste (고준위방사성폐기물 심층처분장 모델링을 위한 불연속체 기반 수리-역학 복합거동 해석기법 현황 분석)

  • Kwon, Saeha;Kim, Kwang-Il;Lee, Changsoo;Kim, Jin-Seop;Min, Ki-Bok
    • Tunnel and Underground Space
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    • v.31 no.5
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    • pp.309-332
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    • 2021
  • Natural barrier systems surrounding the geological repository for the high-level radioactive waste should guarantee the hydraulic performance for preventing or delaying the leakage of radionuclide. In the case of the behavior of a crystalline rock, the hydraulic performance tends to be decided by the existence of discontinuities, so the coupled hydro-mechanical(HM) processes on the discontinuities should be characterized. The discontinuum modelling can describe the complicated behavior of discontinuities including creation, propagation, deformation and slip, so it is appropriate to model the behavior of a crystalline rock. This paper investigated the coupled HM processes in discontinuum modelling such as UDEC, 3DEC, PFC, DDA, FRACOD and TOUGH-UDEC. Block-based discontinuum methods tend to describe the HM processes based on the fluid flow through the discontinuities, and some methods are combined with another numerical tool specialized in hydraulic analysis. Particle-based discontinuum modelling describes the overall HM processes based on the fluid flow among the particles. The discontinuum methods that are currently available have limitations: exclusive simulations for two-dimension, low hydraulic simulation efficiency, fracture-dominated fluid flow and simplified hydraulic analysis, so it could be improper to the modelling the geological repository. Based on the concepts of various discontinuum modelling compiled in this paper, the advanced numerical tools for describing the accurate coupled HM processes of the deep geological repository should be developed.

Korean Part-Of-Speech Tagging by using Head-Tail Tokenization (Head-Tail 토큰화 기법을 이용한 한국어 품사 태깅)

  • Suh, Hyun-Jae;Kim, Jung-Min;Kang, Seung-Shik
    • Smart Media Journal
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    • v.11 no.5
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    • pp.17-25
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    • 2022
  • Korean part-of-speech taggers decompose a compound morpheme into unit morphemes and attach part-of-speech tags. So, here is a disadvantage that part-of-speech for morphemes are over-classified in detail and complex word types are generated depending on the purpose of the taggers. When using the part-of-speech tagger for keyword extraction in deep learning based language processing, it is not required to decompose compound particles and verb-endings. In this study, the part-of-speech tagging problem is simplified by using a Head-Tail tokenization technique that divides only two types of tokens, a lexical morpheme part and a grammatical morpheme part that the problem of excessively decomposed morpheme was solved. Part-of-speech tagging was attempted with a statistical technique and a deep learning model on the Head-Tail tokenized corpus, and the accuracy of each model was evaluated. Part-of-speech tagging was implemented by TnT tagger, a statistical-based part-of-speech tagger, and Bi-LSTM tagger, a deep learning-based part-of-speech tagger. TnT tagger and Bi-LSTM tagger were trained on the Head-Tail tokenized corpus to measure the part-of-speech tagging accuracy. As a result, it showed that the Bi-LSTM tagger performs part-of-speech tagging with a high accuracy of 99.52% compared to 97.00% for the TnT tagger.

Simplification Method for Lightweighting of Underground Geospatial Objects in a Mobile Environment (모바일 환경에서 지하공간객체의 경량화를 위한 단순화 방법)

  • Jong-Hoon Kim;Yong-Tae Kim;Hoon-Joon Kouh
    • Journal of Industrial Convergence
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    • v.20 no.12
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    • pp.195-202
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    • 2022
  • Underground Geospatial Information Map Management System(UGIMMS) integrates various underground facilities in the underground space into 3D mesh data, and supports to check the 3D image and location of the underground facilities in the mobile app. However, there is a problem that it takes a long time to run in the app because various underground facilities can exist in some areas executed by the app and can be seen layer by layer. In this paper, we propose a deep learning-based K-means vertex clustering algorithm as a method to reduce the execution time in the app by reducing the size of the data by reducing the number of vertices in the 3D mesh data within the range that does not cause a problem in visibility. First, our proposed method obtains refined vertex feature information through a deep learning encoder-decoder based model. And second, the method was simplified by grouping similar vertices through K-means vertex clustering using feature information. As a result of the experiment, when the vertices of various underground facilities were reduced by 30% with the proposed method, the 3D image model was slightly deformed, but there was no missing part, so there was no problem in checking it in the app.

A Lifelog Management System Based on the Relational Data Model and its Applications (관계 데이터 모델 기반 라이프로그 관리 시스템과 그 응용)

  • Song, In-Chul;Lee, Yu-Won;Kim, Hyeon-Gyu;Kim, Hang-Kyu;Haam, Deok-Min;Kim, Myoung-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.9
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    • pp.637-648
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    • 2009
  • As the cost of disks decreases, PCs are soon expected to be equipped with a disk of 1TB or more. Assuming that a single person generates 1GB of data per month, 1TB is enough to store data for the entire lifetime of a person. This has lead to the growth of researches on lifelog management, which manages what people see and listen to in everyday life. Although many different lifelog management systems have been proposed, including those based on the relational data model, based on ontology, and based on file systems, they have all advantages and disadvantages: Those based on the relational data model provide good query processing performance but they do not support complex queries properly; Those based on ontology handle more complex queries but their performances are not satisfactory: Those based on file systems support only keyword queries. Moreover, these systems are lack of support for lifelog group management and do not provide a convenient user interface for modifying and adding tags (metadata) to lifelogs for effective lifelog search. To address these problems, we propose a lifelog management system based on the relational data model. The proposed system models lifelogs by using the relational data model and transforms queries on lifelogs into SQL statements, which results in good query processing performance. It also supports a simplified relationship query that finds a lifelog based on other lifelogs directly related to it, to overcome the disadvantage of not supporting complex queries properly. In addition, the proposed system supports for the management of lifelog groups by providing ways to create, edit, search, play, and share them. Finally, it is equipped with a tagging tool that helps the user to modify and add tags conveniently through the ion of various tags. This paper describes the design and implementation of the proposed system and its various applications.

Studies on the Improvement of the Fishing Efficiency of Purse Seine in the Sea Area of Cheju Island -The Changes of Seine Volume and Tension in the Purseline During Pursing- (제주도 주변해역 선망의 어획성능 향상에 관한 연구 -짐줄 체결 중 선망의 용적과 짐줄의 장력 변화 -)

  • 김석종
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.93-101
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    • 1999
  • A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[{2.79 (d/l)+0.35}t-33.37 (d/l) + 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP {0.57t + 13.36 (d/l)+2.97} Where T is tension (kg) in the purseline during pursing.

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Numerical analysis of FEBEX at Grimsel Test Site in Switzerland (스위스 Grimsel Test Site에서 수행된 FEBEX 현장시험에 대한 수치해석적 연구)

  • Lee, Changsoo;Lee, Jaewon;Kim, Geon-Young
    • Tunnel and Underground Space
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    • v.30 no.4
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    • pp.359-381
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    • 2020
  • Within the framework of DECOVALEX-2019 Task D, full-scale engineered barriers experiment (FEBEX) at Grimsel Test Site was numerically simulated to investigate an applicability of implemented Barcelona basic model (BBM) into TOUGH2-MP/FLAC3D simulator, which was developed for the prediction of the coupled thermo-hydro-mechanical behavior of bentonite buffer. And the calculated heater power, temperature, relative humidity, total stress, saturation, water content and dry density were compared with in situ data monitored in the various sections. In general, the calculated heater power and temperature provided a fairly good agreement with experimental observations, however, the difference between power of heater #1 and that of heater #2 could not captured in the numerical analysis. It is necessary to consider lamprophyre with low thermal conductivity around heater #1 and non-simplified installation progresses of bentonite blocks in the tunnel for better modeling results. The evolutions and distributions of relative humidity were well reproduced, but hydraulic model needs to be modified because the re-saturation process was relatively fast near the heaters. In case of stress evolutions due to the thermal and hydraulic expansions, the computed stress was in good agreement with the data. But, the stress is slightly higher than the measured in situ data at the early stage of the operation, because gap between rock mass and bentonite blocks have not been considered in the numerical simulations. The calculated distribution of saturation, water content, and dry density along the radial distance showed good agreement with the observations after the first and final dismantling. The calculated dry density near the center of the FEBEX tunnel and heaters were overestimated compared with the observations. As a result, the saturation and water content were underestimated with the measurements. Therefore, numerical model of permeability is needed to modify for the production of better numerical results. It will be possible to produce the better analysis results and more realistically predict the coupled THM behavior in the bentonite blocks by performing the additional studies and modifying the numerical model based on the results of this study.

Comparative Evaluation of Colon Cancer Stemness and Chemoresistance in Optimally Constituted HCT-8 cell-based Spheroids (적정 구성 배양 HCT-8 기반 대장암 스페로이드의 암 줄기세포능 및 항암제 내성 평가의 비교 평가 연구)

  • Lee, Seung Joon;Kim, Hyoung-Kab;Lee, Hyang Burm;Moon, Yuseok
    • Journal of Life Science
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    • v.26 no.11
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    • pp.1313-1319
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    • 2016
  • Cancer is a complex disease heterogeneously composed of various types of cells including cancer stem-like cells responsible for relapse and chemoresistance in the tumor microenvironment. The conventional two-dimensional cell culture-based platform has critical limitations for representing the heterogeneity of cancer cells in the three-dimensional tumor niche in vivo. To overcome this insufficiency, three-dimensional cell culture methods in a scaffold-dependent or -free physical environment have been developed. In this study, we improved and simplified the HCT-8 colon cancer cell-based spheroid culture protocol and evaluated the relationship between cancer stemness and responses of chemosensitivity to 5- Fluorouracil (5-FU), a representative anticancer agent against colon cancer. Supplementation with defined growth factors in the medium and the culture dish of the regular surface with low attachment were required for the formation of constant-sized spheroids containing $CD44^+$ and $CD133^+$ colon cancer stem cells. The chemo-sensitivities of $CD44^+$ cancer stem cells in the spheroids were much lower than those of $CD44^-$ non-stem-like cancer cells, indicating that the chemoresistance to 5-FU is due to the stemness of colon cancer cells. Taken together, the inflammation and oncogenic gut environment-sensitive HCT-8 cell-based colon cancer spheroid culture and comparative evaluation using the simplified model would be an efficient and applicable way to estimate colon cancer stemness and pharmaceutical response to anticancer drugs in the realistic tumor niche.

A Study of Dopamine Transporter Imaging and Comparison of Noninvasive Simplified Quantitative Methods in Normal Controls and Parkinson's Patients ([I-123]IPT SPECT를 이용한 정상인과 파킨슨 환자의 도파민 운반체의 영상화 및 단순화된 정량분석 방법들의 비교연구)

  • Bong, Jung-Kyun;Kim, Hee-Joung;Im, Joo-Hyuck;Yang, Seoung-Oh;Moon, Dae-Hyuk;Ryu, Jin-Sook;Nam, Ki-Pyo;Cheon, Jun-Hong;Kwon, Soo-Il;Lee, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.3
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    • pp.315-324
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    • 1996
  • The purpose of this study was to compare the specific binding ratio method with model-based methods in estimating the transporter parameter $k_3/k_4$ in normal controls and Parkinson's patients with [I-123]IPT SPECT and to evaluate the usefulness of [I-123]IPT SPECT. $6.5{\pm}1.1$ mCi ($239.0{\pm}40.3$ MBq) of [$^{123}I$]IPT was intravenouly injected as a bolus into six normal controls(age:$45{\pm}13$) and seventeen patients(age:$55{\pm}8$) with Pakinson's disease(PD). The transporter parameter $k_3/k_4$ was derived using the Ichise's graphical method($R_v$) and Lassen's area ratio method($R_A$) for the dynamic IPT SPECT data without blood samples. Then, the relationships between the transporter parameter $R-v,\;R_A$ and the ratio of (BG-OCC)/OCC at 115 minutes were evaluated by linear regression analysis. $R_vs$ by Ichise's graphical method for NC and PD were $2.08{\pm}0.29$ and $0.78{\pm}0.31$, respectively. $R_As$ by Lassen's area ratio method for NC and PD were $1.48{\pm}0.16$ and $0.65{\pm}0.24$, respectively. The correlation coefficients between (BG-OCC)/OCC and $R_v$, (BG-OCC)/OCC and $R_A$, and $R_v$ and $R_A$ were 0.93, 0.90, 0.99 and their corresponding slopes were 0.54, 0.34, and 0.65, respectively. The $R_v$ and $R_A$ of NC were significantly higher than the ones of PD. That is, the $k_3/k_4$ of NC was clearly separated from the one of PD. $k_3/k_4$ showed a good correlation with the ratio of (BG-OCC)/OCC. The results indicate that the noninvasive simplified quantitative methods may be useful to measure the transporter parameter $k_3/k_4$ and the specific binding ratio method can be used for quantitative studies of dopamine transporter with [I-123]IPT SPECT in humans brains.

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A Study of Feasibility of Dipole-dipole Electric Method to Metallic Ore-deposit Exploration in Korea (국내 금속광 탐사를 위한 쌍극자-쌍극자 전기탐사의 적용성 연구)

  • Min, Dong-Joo;Jung, Hyun-Key;Park, Sam-Gyu;Chon, Hyo-Taek;Kwak, Na-Eun
    • Geophysics and Geophysical Exploration
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    • v.11 no.3
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    • pp.250-262
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    • 2008
  • In order to assess the feasibility of the dipole-dipole electric method to the investigation of metallic ore deposit, both field data simulation and inversion are carried out for several simplified ore deposit models. Our interest is in a vein-type model, because most of the ore deposits (more than 70%) exist in a vein type in Korea. Based on the fact that the width of the vein-type ore deposits ranges from tens of centimeters to 2m, we change the width and the material property of the vein, and we use 40m-electrode spacing for our test. For the vein-type model with too small width, the low resistivity zone is not detected, even though the resistivity of the vein amounts to 1/300 of that of the surrounding rock. Considering a wide electrode interval and cell size used in the inversion, it is natural that the size of the low resistivity zone is overestimated. We also perform field data simulation and inversion for a vein-type model with surrounding hydrothermal alteration zones, which is a typical structure in an epithermal ore deposits. In the model, the material properties are assumed on the basis of resistivity values directly observed in a mine originated from an epithermal ore deposits. From this simulation, we can also note that the high resistivity value of the vein does not affect the results when the width of the vein is narrow. This indicates that our main target should be surrounding hydrothermal alteration zones rather than veins in field survey. From these results, we can summarize that when the vein is placed at the deep part and the difference of resistivity values between the vein and the surrounding rock is not large enough, we cannot detect low resistivity zone and interpret the subsurface structures incorrectly using the electric method performed at the surface. Although this work is a little simple, it can be used as references for field survey design and field data Interpretation. If we perform field data simulation and inversion for a number of models and provide some references, they will be helpful in real field survey and interpretation.

Channel Model and Wireless Link Performance Analysis for Short-Range Wireless Communication Applications in the Terahertz Frequency (테라헤르츠 대역 주파수에서 근거리 무선 통신 응용을 위한 채널 모델 및 무선 링크 성능 분석)

  • Chung, Tae-Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.9
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    • pp.868-882
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    • 2009
  • In this paper, channel model and wireless link performance analysis for the short-range wireless communication system applications in the terahertz frequency which is currently interested in many countries will be described. In order to realize high data rates above 10 Gbps, the more wide bandwidths will be required than the currently available bandwidths of millimeter-wave frequencies, therefore, the carrier frequencies will be pushed to THz range to obtain larger bandwidths. From the THz atmospheric propagation characteristics based on ITU-R P.676-7, the available bandwidths were calculated to be 68, 48 and 45 GHz at the center frequencies of 220, 300 and 350 GHz, respectively. With these larger bandwidths, it was shown from the simulation that higher data rate above 10 Gbps can be achieved using lower order modulation schemes which have spectral efficiency of below 1. The indoor propagation delay spread characteristics were analyzed using a simplified PDP model with respect to building materials. The RMS delay spread was calculated to be 9.23 ns in a room size of $6\;m(L){\times}5\;m(W){\times}2.5\;m(H)$ for the concrete plaster with TE polarization, which is a similar result of below 10 ns from the Ray-Tracing simulation in the reference paper. The indoor wireless link performance analysis results showed that receiver sensitivity was $-56{\sim}-46\;dBm$ over bandwidth of $5{\sim}50\;GHz$ and antenna gain was calculated to be $26.6{\sim}31.6\;dBi$ at link distance of 10m under the BPSK modulation scheme. The maximum achievable data rates were estimated to be 30, 16 and 12 Gbps at the carrier frequencies of 220, 300 and 350 GHz, respectively, under the A WGN and LOS conditions, where it was assumed that the output power of the transmitter is -15 dBm and link distance of 1 m with BER of $10^{-12}$. If the output power of transmitter is increased, the more higher data rate can be achieved than the above results.