• Communications of Mathematical Education
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• v.37 no.1
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• pp.65-84
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• 2023

The method of Lagrange multipliers, one of the most fundamental algorithms for solving equality constrained optimization problems, has been widely used in basic mathematics for artificial intelligence (AI), linear algebra, optimization theory, and control theory. This method is an important tool that connects calculus and linear algebra. It is actively used in artificial intelligence algorithms including principal component analysis (PCA). Therefore, it is desired that instructors motivate students who first encounter this method in college calculus. In this paper, we provide an integrated perspective for instructors to teach the method of Lagrange multipliers effectively. First, we provide visualization materials and Python-based code, helping to understand the principle of this method. Second, we give a full explanation on the relation between Lagrange multiplier and eigenvalues of a matrix. Third, we give the proof of the first-order optimality condition, which is a fundamental of the method of Lagrange multipliers, and briefly introduce the generalized version of it in optimization. Finally, we give an example of PCA analysis on a real data. These materials can be utilized in class for teaching of the method of Lagrange multipliers.

• Journal of the Korea Computer Graphics Society
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• v.12 no.4
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• pp.23-32
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• 2006

In recent years, since the digital camera has been popularized, so users can easily collect hundreds of photos in a single usage. Thus the managing of hundreds of digital photos is not a simple job comparing to the keeping paper photos. We know that managing and classifying a number of digital photo files are burdensome and annoying sometimes. So people hope to use an automated system for managing digital photos especially for their own purposes. The previous studies, e.g. content-based image retrieval, were focused on the clustering of general images, which it is not to be applied on digital photo clustering and classification. Recently, some specialized clustering algorithms for images clustering digital camera images were proposed. These algorithms exploit mainly the statistics of time gap between sequent photos. Though they showed a quite good result in image clustering for digital cameras, still lots of improvements are remained and unsolved. For example the current tools ignore completely the image transformation with the different focal lengths. In this paper, we present a photo considering focal length information recorded in EXIF. We propose an algorithms based on MVA(Matching Vector Analysis) for classification of digital images taken in the every day activity. Our experiment shows that our algorithm gives more than 95% success rates, which is competitive among all available methods in terms of sensitivity, specificity and flexibility.

• Journal of the Korean Society of Costume
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• v.55 no.4 s.94
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• pp.62-78
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• 2005

The modern period was the time that the most radical and extensive social and mental changes were occurring throughout the history, and modernism was prevailing as a general cognition system of people. Modernism, which carries principles of progress, belief in application of scientific technology, worship of reason, ideal of liberty as a col-e value of civilization, was plated as a leading ideology in the realm of society, culture and art In the early 20th century. In this study, the formative characteristics of modernism seen in architecture and fashion are analogized and analyzed in four ways ell the basis of the theory of p. Greenhalgh. First, 'Standardization for mass-production', which is analogized which P. Greenhalgh's 'Decompart-mentalisation', 'Social Morality', and' Technology'. Standardization for mass-production in architecture focuses on the development of a design prototype in order to mass produce; the development of ready-made clothes is actively done ill the fashion area for the same purpose as well. Second, 'Rational functionality' coming from P. Greenhalgh's 'The total work of art' and 'Function'. While rational functionality in architecture puts an emphasis on the rational operation of all the functions in regard to the relation between each part and the whole, rational functionality in fashion call be mainly seen in a dramatic increase in physical activity which could be hardly found before the modernism period. Namely, all the fashion design elements are developed for a certain rational and functional design on each part as well as on the whole in order to greatly increase physical activity. Third, 'the pursuit for genuineness of objects and universality of beauty' is on the analogy of P Greenhalgh's 'Truth', 'Anti-historicism', 'Abstraction', 'Internationalism/Universality'. This idea is adopted in architecture in the form of design of geometrical abstraction. In the same way, design using geometrical abstraction comes to have a significant meaning in fashion of the modernism period. So to speak, modernism architecture and fashion can be reborn to become an inter·national style by giving up the decorative and regional design prevailing before modernism and by expressing universal aesthetics in the form of simplicity and abstraction instead. Fourth, 'Expression of progress through a change in a viewpoint' stems from P. Greenhalgh's 'Progress', 'Transformation of Consciousness', 'Theology'. In architecture, this concept appears by using new construction materials and methods and by representing new aesthetical idea. As a result, it makes it possible for people to make progress for better lives. Like in architecture, new attempts for material application and processing are made in fashion. This gives rise to a general change in a viewpoint related to fashion, so that a flew fashion design which there has never been before can come out.

• Journal of the Mineralogical Society of Korea
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• v.25 no.4
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• pp.283-293
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• 2012

In order to have better insights into the chemical differentiation of Earth from its magma ocean phase to the current stratified structure, detailed information of crystallization kinetics of silicate melts consisting of the magma ocean is essential. The structural transitions in oxide glasses and melts upon crystallization provide improved prospects for a systematic and quantitative understanding of the crystallization processes. Here, we report the $^{27}Al$ 3QMAS NMR spectra for sol-gel synthesized $Al_2O_3$ glass with varying temperature and annealing time. The NMR spectra for the amorphous $Al_2O_3$ show well-resolved Al coordination environments, characterized with mostly $^{[4,5]}Al$ and a minor fraction of $^{[6]}Al$. The fraction of $^{[5]}Al$ in the alumina phase decreases with increasing annealing time at constant temperature. The NMR results of $Al_2O_3$ phases also imply that multiple processes (e.g., crystallization and/or changes in structural disorder within glasses) could involve upon its phase transition. The current results and method can be useful to understand crystallization kinetics of diverse natural and multi-component silicate glasses and melts. The potential result may yield atomic-level understanding of Earth's chemical evolution and differentiation from the magma ocean.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.125-132
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• 2010

Rice is the staple food of more than 50% of the worlds population. Cultivated rice has the AA genome (diploid, 2n=24) and small genome size of only 430 megabase (haploid genome). As the sequencing of rice genome was completed by the International Rice Genome Sequencing Project (IRGSP), many researchers in the world have been working to explore the gene function on rice genome. Insertional mutagenesis has been a powerful strategy for assessing gene function. In maize, well characterized transposable elements have traditionally been used to clone genes for which only phenotypic information is available. In rice endogenous mobile elements such as MITE and Tos (Hirochika. 1997) have been used to generate gene-tagged populations. To date T-DNA and maize transposable element systems has been utilized as main insertional mutagens in rice. A main drawback of a T-DNA scheme is that Agrobacteria-mediated transformation in rice requires extensive facilities, time, and labor. In contrast, the Ac/Ds system offers the advantage of generating new mutants by secondary transposition from a single tagged gene. Revertants can be utilized to correlate phenotype with genotype. To enhance the efficiency of gene detection, advanced gene-tagging systems (i.e. activation, gene or enhancer trap) have been employed for functional genomic studies in rice. Internationally, there have been many projects to develop large scales of insertionally mutagenized populations and databases of insertion sites has been established. Ultimate goals of these projects are to supply genetic materials and informations essential for functional analysis of rice genes and for breeding using agronomically important genes. In this report, we summarize the current status of Ac/Ds-mediated gene tagging systems that has been launched by collaborative works from 2001 in Korea.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.36-37
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• 1990

In the past, facile dissolution of cellulose has been hampered by the lack of suitable nondegrading solvents. Recently, this problem has been solved in our laboratory by the discovery of an inexpensive, convenient solvent system, that is the mixture of $NH_3\;and\;NH_4SCN$, for cellulose. Also, the $cellulose/NH_3/NH_4SCN$ solution system has been found to form the anisotropic, i.e., liquid crystalline phase. It is believed that both the cholesterio and the nematic phase occur. This finding has prompted extensive on-going researoh on the formation of the liquid crystalline phase from an inexpensive natural source such as cellulose since the nematic phase is envisioned as an excellent precursor sources for products with desirable properties, for example, high modulus and high strength. This interest naturally leads to a desire to understand the theological properties of the nematic phase so that the transformation of the nematic phase to the solid state with desirable properties can be efficiently accomplished, ;From this point of view, the theological behavior of the $cellulose/NH3_/NH_4SCN$ system has been studied as a function of shear rate and shear stress over a wide range of solvent compositions, cellulose concentration, centrifugation and urea contents, Results indicate that the viscosity decreases with increasing shear rate. A marked shear thinning behavior and a quasi-Newtonian behavior were observed in the low shear rate region and in the high shear rate region, respectively for all solvent compositions. The $cellulose/NH_3/NH_4SCN$ solution system only exhibited the viscosity increase with increasing cellulose concentration and failed to show the viscosity drop generally observed at the point of incipience of liquid crystal formation, This may be due to the gel-like nature of the solution by the association of the rodlike molecules into bundles which may serve as crosslinking points giving the cellulose solution a network structure. Also, simply hydrogen bonding may be so restrictive of molecular mobility that a viscosity drop is blocked. In addition to the above results, yield stress and thixotropy were also observed in the $cellulose/NH_3/NB_4SCN$ solution system which are characteristics of liquid crystal and gel, The results of the effect of centrifugation on viscosity show that viscosity decreases by the application of centrifugation. This may be explained by the change of the piled polydomain structure to the dispersed polydomain structure due to the pressure gradient generated during centrifugation.ation.

• 사회경제평론
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• v.31 no.3
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• pp.203-237
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• 2018

This paper critically studies Meidner's wage-earner funds project. On the basis of this, this paper intends to create new prospects for a universal welfare regime. From the perspective of the welfare system, the funds project is a correction or supplement of the Swedish welfare system of the Swedish model centered on 'redistribution'. However, the funds project shares the ideology of Swedish model and its fundamental premise, I.e. guild socialism and labor-centrism. This paper discusses the limitations of the funds project resulting from this, especially with regard to its three purposes: equalization of property distribution, economic democracy and the correction of excess profit. It then highlights that the alternative to overcome the limitations of the funds project and the Swedish universal welfare system should be based on a new ideology and fundamental premise that is cut off from guild socialism and labor centrism. As an alternative fulfilling this, this paper focuses on theories that suggest that the Common Wealth Fund should be created and basic income should be implemented in the form of dividends as its dividend. As a result, Commons Capital Stock and the basic income as its dividend are presented as alternative prospects for the funds project.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.403-421
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• 2021

Most of the urban tunnels in Korea, which are represented by the 1st to 3rd subways, use the drainage tunnel by NATM. Recently, when a construction project that actively utilizes large-scale urban space is promoted, negative effects that do not conform to the existing empirical rules of urban tunnels may occur. In particular, there is a high possibility that groundwater fluctuations and hydrodynamic behavior will occur owing to the practice of tunnel technology in Korea, which has mainly applied the drainage tunnel. In order to solve the problem of the drainage tunnel, attempts are being made to control groundwater fluctuations. For this, the establishment of tunnel groundwater management standard concept and the analysis of the tunnel hydraulic behavior were performed. To prevent the problem of groundwater fluctuations caused by the construction of large-scale tunnels in urban areas, it was suggested that the conceptual transformation of the empirical technical practice, which is applied only in the underground safety impact assessment stage, to the direction of controlling the inflow in the tunnel, is required. And the relationship between the groundwater level and the inflow of the tunnel required for setting the allowable inflow when planning the tunnel was derived. The introduction of a tunnel groundwater management concept is expected to help solve problems such as groundwater fluctuations, ground settlement, depletion of groundwater resources, and decline of maintenance performance in various urban deep tunnel construction projects to be promoted in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.28-41
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• 2022

A road system with CV(Connected Vehicle)s, which is often referred to as a cooperative intelligent transportation system (C-ITS), provides various road information to drivers using an in-vehicle warning system. Road environments with CVs induce drivers to reduce their speed or change lanes to avoid potential risks downstream. Such avoidance maneuvers can be considered to improve driving behaviors from a traffic safety point of view. Thus, empirically evaluating how a given in-vehicle warning information affects driving behaviors, and monitoring of the correlation between them are essential tasks for traffic operators. To quantitatively evaluate the effect of in-vehicle warning information, this study develops a method to calculate compliance rate of drivers where two groups of speed profile before and after road information is provided are compared. In addition, conventional indexes (e.g., jerk and acceleration noise) to measure comfort of passengers are examined. Empirical tests are conducted by using PVD (Probe Vehicle Data) and DTG (Digital Tacho Graph) data to verify the individual effects of warning information based on C-ITS constructed in Seoul metropolitan area in South Korea. The results in this study shows that drivers tend to decelerate their speed as a response to the in-vehicle warning information. Meanwhile, the in-vehicle warning information helps drivers to improve the safety and comport of passengers.

• Korean Journal of Culture and Social Issue
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• v.14 no.1_spc
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• pp.427-468
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• 2008

This article examines the role and influence of educational achievement on Korean society and its future. Four major factors that associated with and influence educational achievement in Korea (i.e., trust, efficacy beliefs, quality of life, and societal transformation) are reviewed. First, the role of educational achievement on establishing a basis for trust in Korean society is examined. By reviewing studies of perception of Korean society, people and institutions, the importance of establishing trust in Korean society is outlined. Second, the role of efficacy belief in promoting educational achievement is examined. The importance of collective efficacy, at the adolescent, adult and political levels is emphasized. In addition, the concept and application of self-efficacy for teachers and parents is reviewed. Third, the role and influence of educational achievement on quality of life is outlined. Studies indicate that educational achievement plays an important role in improving the quality of life. The pressure to achieve, however, can have negative impact on stress and mental health and support systems need to be developed to alleviate their impact. Fourth, the future and prospects for Korean society through educational achievement is discussed. Through education, the importance of bridging the divide with North Korea is an important agenda for the future of Korean society. Finally, the importance of indigenous psychological perspective in understanding Korean society and providing direction for the future is discussed.