• BMB Reports
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• v.42 no.6
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• pp.315-323
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• 2009

In order to elucidate ultimate biological function of the genome, the model animal system carrying mutations is indispensable. Recently, large-scale mutagenesis projects have been launched in various species. Especially, the mouse is considered to be an ideal model to human because it is a mammalian species accompanied with well-established genetic as well as embryonic technologies. In 1990', large-scale mouse mutagenesis projects firstly initiated with a potent chemical mutagen, N-ethyl-N-nitrosourea (ENU) by the phenotype-driven approach or forward genetics. The knockout mouse mutagenesis projects with trapping/conditional mutagenesis have then followed as Phase II since 2006 by the gene-driven approach or reverse genetics. Recently, the next-generation gene targeting system has also become available to the research community, which allows us to establish and analyze mutant mice carrying an allelic series of base substitutions in target genes as another reverse genetics. Overall trends in the large-scale mouse mutagenesis will be reviewed in this article particularly focusing on the new advancement of the next-generation gene targeting system. The drastic expansion of the mutant mouse resources altogether will enhance the systematic understanding of the life. The construction of the mutant mouse resources developed by the forward and reverse genetic mutagenesis is just the beginning of the annotation of mammalian genome. They provide basic infrastructure to understand the molecular mechanism of the gene and genome and will contribute to not only basic researches but also applied sciences such as human disease modelling, genomic medicine and personalized medicine.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10c
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• pp.103-122
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• 2001

For prediction of ground movement per the excavation step, observational results of ground movement during the construction was very different with prediction during the analysis of design. step because of the uncertainty of the numerical analysis modelling, the soil parameter, and the condition of a construction field, etc. however accuratly numerical analysis method was applied. Therefore, the management system through the construction field measurement should be achieved for grasping the situation during the excavation. Until present, the measurement system restricted by ‘Absolute Value Management system’only analyzing the stability of present step was executed. So, it was difficult situation to expect the prediction of ground movement for the next excavation step. In this situation, it was developed that ‘The Management system TOMAS-EXCAV’ consisted of ‘Absolute value management system’ analyzing the stability of present step and ‘Prediction management system’ expecting the ground movement of next excavation step and analyzing the stability of next excavation step by‘Back Analysis’. TOMAS-EXCAV could be applied to all uncertainty of earth retaining structures analysis by connecting ‘Forward analysis program’ and ‘Back analysis program’ and optimizing the main design variables using SQP-MMFD optimization method through measurement results. The application of TOMAS-EXCAV was confirmed that verifed the three earth retaing construction field by back analysis.

• Journal of the Korean Applied Science and Technology
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• v.15 no.4
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• pp.11-20
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• 1998

The propagation of light radiation in a turbid medium is an important problem that confronts dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. Scattered light is measured as a function of the position(distance r, depth z) between the axis of the incident beam and the detection spot. Turbid sample yields a very forward-directed scattering pattern at short range of position from source to detector, whereas the thicker samples greatly attenuated the on-axis intensity at long range of position. The portions of scattered light reflected from or transmitted throughphantom depend upon internal reflectance and absorption properties of the phantom. Monte Carlo simulation method for modelling light transport in tissue is applied. It uses the photon is moved a distance where it may be scattered, absorbed, propagated, internally reflected, or transmitted out of tissue. The photon is repeatedly moved until it either escape from or is absorbed by the phantom. In order to obtain an optimum therapeutic ratio in phantom material, optimum control the light energy fluence rate is essential. This study is to discuss the physical mechanisms determining the actual light dose in phantom. Permitting a qualitative understanding of the measurements. It may also aid in designing the best model for laser medicine and application of medical engineering.

• Computers and Concrete
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• v.4 no.1
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• pp.1-18
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• 2007

Over the past decades, an enormous amount of effort has been expended in laboratory and field studies on concrete durability estimation. The results of this research are still either widely scattered in the journal literature or mentioned briefly in the standard textbooks. Moreover, the theoretical approaches of deterioration mechanisms with a predictive character are limited to some complicated mathematical models not widespread in practice. A significant step forward could be the development of appropriate software for computer-based estimation of concrete service life, including reliable mathematical models and adequate experimental data. In the present work, the basis for the development of a computer estimation of the concrete service life is presented. After the definition of concrete mix design and structure characteristics, as well as the consideration regarding the environmental conditions where the structure will be found, the concrete service life can be reliably predicted using fundamental mathematical models that simulate the deterioration mechanisms. The prediction is focused on the basic deterioration phenomena of reinforced concrete, such as carbonation and chloride penetration, that initiate the reinforcing bars corrosion. Aspects on concrete strength and the production cost are also considered. Field observations and data collection from existing structures are compared with predictions of service life using the above model. A first attempt to develop a database of service lives of different types of reinforced concrete structure exposed to varying environments is finally included.

• East Asian Economic Review
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• v.22 no.2
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• pp.177-215
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• 2018

Trump's withdrawal from the Trans-Pacific Partnership (TPP) and his "America First" trade agenda ignite a second round of interest in mega-free trade agreements in the Asia-Pacific. Countries are evaluating alternative trade policy actions in a post-TPP era. Using national real GDP gains estimated by a modified GTAP model to construct "preference ordering" for 10 Association of Southeast Asian Nations members and their six regional dialogue partners, this paper comes up with several policy-oriented findings. First, when multilateral agreements are not possible, countries are better off with a regional trading agreement than without one. Second, the Regional Comprehensive Economic Partnership is likely to have higher beneficial impacts than the Comprehensive and Progressive Agreement for Trans-Pacific Partnership. Third, for dual-track countries, implementing both agreements is better than each separately. Fourth, impacts of open regionalism are likely to be higher than those of a closed and reciprocal one. Going forward, this paper argues that countries should adopt a "multi-track, multi-stage" approach to trade policy.

• East Asian Economic Review
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• v.18 no.4
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• pp.425-461
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• 2014

This paper analyzes the impact of the Canada-Korea Free Trade Agreement on the basis of the published text and agreed schedule of commitments. We find that the Agreement reinforces existing patterns of comparative advantage between Canada (agriculture and resource-based sectors) and Korea (autos and other industries). The sensitive sectors that held up the deal for years - autos into Canada and beef into Korea - witness major trade gains, but are not unduly disrupted. In both economies, the major output gains otherwise come in non-traded services sectors, driven by income effects. We find that trade diversion effects are quite significant; this lends support for the domino theory of major free trade agreements - since the Korea-EU agreement broke the ice, the pressure has intensified on third parties to re-level playing fields by striking their own deals. The study breaks new ground in modelling services trade by developing policy impacts based on the extent to which the text of the Agreement modifies Korea's and Canada's scores on the OECD's Services Trade Restrictiveness Index and by providing estimates of Mode 3 Services trade impacts. The analysis of the Agreement as negotiated, the present study, in our view, is a step forward in understanding the impact of modern free trade agreements.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.195-195
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• 2012

인공신경망 모형은 복잡하고 비선형의 입력과 출력 관계를 잘 반영할 수 있어서 유출 모델링에 널리 적용되어 왔다. 그러나 인공신경망 모형은 강우나 유역특성의 공간적 분포를 반영하는 것이 어려우며 물리적 개념이 결여되어 있는 단점이 있다. 본 연구에서는 유역특성과 물리적 개념을 반영할 수 있는 물리기반 모형과 인공신경망 모형의 장점들을 조합하여 물리기반 모형의 일 유출량 해석 능력을 향상하기 위하여 SWAT 모형과 인공신경망(ANN)을 연계하였다. SWAT-ANN 연계모형은 두 단계로 구성되어 진다. 첫 번째 단계에서는 관측 자료를 이용하여 SWAT 모형을 보정한다. 두 번째 단계에서는 첫 번째 단계에서 계산한 소유역별 SWAT 모형의 유출결과를 ANN의 입력자료로 이용하여 SWAT-ANN 연계모형을 구축한다. SCE-UA 최적화 방법을 적용하여 SWAT 모형의 매개변수들을 보정하였고, ANN 학습은 3층의 feed-forward 역전파 알고리즘에 기초한 Bayesian Regularization 방법을 적용하였다. ANN 은닉층의 뉴런 및 전달함수는 시행착오를 통하여 적절한 ANN 구조를 설정하여 SWAT-ANN 연계모형의 일유출량을 모의하였다. 여러 가지 통계적 오차기준을 이용하여 보청천 유역에서 SWAT-ANN 연계모형의 결과와 SWAT 단독 모형의 결과를 비교하였다. SWAT-ANN 연계모형이 SWAT 단독 모형보다 더 우수한 결과를 나타내어 일 유출량 해석을 위한 SWAT-ANN 연계모형의 유용성을 확인할 수 있었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.555-563
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• 2020

Foward-swept wings are known to possess superior aerodynamic performance compared to the conventional straight wings. However major concerns regarding forward-swept wings include divergence at lower airspeeds which require careful consideration at the design stage. As an endeavor to overcome such drawbacks, aeroelastic tailoring is attempted. In order to find an optimal ply sequence, recursive aeroelastic analyses is conducted and one-dimensional beam analysis coupled with simple aerodynamics is used for the improved computational efficiency and modelling convenience. The analysis used in this paper, DYMORE and analytic formula, both use one-dimensional beam model for the structure. Cross-sectional analysis for multi-cell NACA0015 airfoil section is conducted using VABS and oblique function is used for the sweep angle. Throughout the present aeroelastic tailoring, the maximum divergence speed of 290.2m/s is achieved which is increased by approximately 43% than that for the conventional ply configuration.

• Geophysics and Geophysical Exploration
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• v.16 no.1
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• pp.27-35
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• 2013

In this study, we developed the trial product on 3D magnetic inversion tentatively named 'KMag3D'. Also, we briefly introduced its own function and graphic user interface on which especially focused through the development in the form of user manual. KMag3D is consisted of two fundamental frame for the 3D magnetic inversion. First, algebraic reconstruction technique was selected as a 3D inversion algorithm instead of least square method conventionally used in various magnetic inversion. By comparison, it was turned out that algebraic reconstruction algorithm was more effective and economic than that of least squares in aspect of both computation time and memory. Second, for the effective determination of the 3D initial and a-priori information model required in the execution of our algorithm, we proposed the practical technique based on the assemblage of 2D forward modeling and inversion results for individual user-selected 2D profiles. And in succession, initial and a-priori information model were constructed by appropriate interpolation along the strke direction. From this, we concluded that our technique is both suitable and very practical for the application of 3D magentic inversion problem.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.1-8
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• 2010

Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.