• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.55-60
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• 2009

This paper deals with the analysis of characteristics of the scale non-uniformly formed on the surface of the steel during the steel production processes. The steel made at the high temperature contacts with the oxygen in the air, so forms the scale immediately. The scale has a role to protect the surface of the steel product as a oxide-layer, but the scale formed non-uniformly spoils the exterior of the steel product and occurs the problems about the next processes. There is a pickling process to remove the scale of the steel products, but the real situation is that the pickling process is not also based on the analysis of the characteristics of the scale. Therefore, this paper describe the procedures of the analysis of the scale more effectively using the radio-frequency wave. Using the radio-frequency wave, this paper introduce the experimentations to analyze the distributions of scale, the junction characteristics between the surface of steel and scale and the distributions of scale on the produced steel coil. Also, according to the simple simulations, this paper proves the proprieties about the above contents.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1468-1480
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• 1999

In database systems, join operations are the most complex and time consuming ones which limit performance of such system. Many parallel join algorithms have been proposed for the systems. However, they did not consider data skew, such as attribute value skew (AVS) and join product skew (JPS). In the skewness environments, performance of framework for a uniform load distribution and an efficient parallel join algorithm using the framework to handle AVS and JPS. In our algorithm, we estimate data distributions of input and output relations of join operations using the sampling methodology and evaluate join cost for the estimated data distributions. Finally, using the histogram equalization method we distribute data among nodes to achieve good load balancing among nodes in the local joining phase. For performance comparison, we present simulation model of our algorithm and other join algorithms and present the result of some simulation experiments. The results indicate that our algorithm outperforms other algorithms in the skewed case.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.58-66
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• 2013

This study investigated quality properties of alkali activated cement free mortar using industrial by-product such as cement kiln dust(CKD), silica fume(SF) and quartz sand powder(SP) to compare with previous research about blast furnace slag(BS) and fly ash(FA). The results were as following. All materials were effective to increase compressive strength, however they showed different tendency on flowability. CKD and SP increased flowability, but on the other hand SF did not because it's blain was great difference with other materials. Flowability and compressive strength were related with grading distributions of binders because CKD, SP and SF which had small particle size filled up BS and FA. Application of industrial by-products with various grading distributions could be effective for the high early strength and flowability of alkali activated cement free mortar using BS.

• Structural Engineering and Mechanics
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• v.9 no.3
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• pp.269-288
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• 2000

The governing differential equations for free vibration of multi-step orthotropic shear plates with variably distributed mass, stiffness and viscous damping are established. It is shown that a shear plate can be divided into two independent shear bars to determine the natural frequencies and mode shapes of the plate. The jk-th natural frequency of a shear plate is equal to the square root of the square sum of the j-th natural frequency of a shear bar and the k-th natural frequency of another shear bar. The jk-th mode shape of the shear plate is the product of the j-th mode shape of a shear bar and the k-th mode shape of another shear bar. The general solutions of the governing equations of the orthotropic shear plates with various boundary conditions are derived by selecting suitable expressions, such as power functions and exponential functions, for the distributions of stiffness and mass along the height of the plates. A numerical example demonstrates that the present methods are easy to implement and efficient. It is also shown through the numerical example that the selected expressions are suitable for describing the distributions of stiffness and mass of typical multi-storey buildings.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.589-596
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• 2012

In this paper, the reactive dynamics properties of the reactions Ba + $C_6H_5Br$ and Ba + m-$C_6H_4CH_3Br$ were studied by means of the quasi-classical trajectory method based on the London-Eyring-Polanyi-Sato potential energy surfaces. The vibrational distributions, reaction cross sections, rotational alignments of the products BaBr all were obtained. The peak values of the vibrational distributions are located at $\nu$ = 0 for the reactions Ba + $C_6H_5Br$ and Ba + m-$C_6H_4CH_3Br$ when the collision energies are 1.09 and 1.10 eV, respectively. The reaction cross sections increase with the increasing collision energy, which changes from 0.6 to 1.5 eV. The product rotational alignments deviate from -0.5 and firstly increase and then decrease while the collision energy is increasing, just like that of Heavy+Light-Light system.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.470-480
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• 2015

There are many challenges in manufacturing system for new factory construction. Although factories produce same product, the layout of each factory may be different. The body shop in an automotive factory is a typical flow line with assembly, but the layout concept of the line varies among factories. In this paper, two types of layouts in the body shops of automotive factories, one for layered build and the other for modular build, are compared using simulation study. The simulation experiments indicate that the modular build layout is better than the layered build layout with respect to production rate. The effects of various failure distributions on the throughputs are also investigated, and some insights are suggested regarding the layout concept.

• Journal of Distribution Science
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• v.20 no.8
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• pp.123-133
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• 2022

Purpose: As moment-based marketing messages (i.e., messages related to current moments or event), companies put significant investments to distribute TV advertising related to external moments in a retail environment. While the literature offers strong support for the value of distributions of context-based messaging to advertisers, less attention has been given to how to design those messages to effectively communicate across channels. This research adds a new dimension of analysis to the study of advertising context and its cross-channel effects on online consumer behavior. Research Design, Data and Methodology: A system-of-equations Tobit regression model was adopted using data collected from an advertising agency that consists of 1,223 TV ads aired during the Rio Olympics and NCAA, tagging from consumers, and a text analysis. Results: First, TV ads with high centrality of context lead to lower online search behavior and higher online social actions. Second, how brands can design messages more effectively was explored by using product information as a moderator that could improve the impact of context-based TV advertisements. Conclusions: Given that expenses in traditional channels are still one of the biggest channel management decisions, it is critical to understand how consumer engagement varies by design of context-based TV advertising.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.745-752
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• 2009

In robust design, the mean and variance of design performance are frequently used to measure the design performance and its robustness under uncertainties. In this paper, we present the Gauss-type quadrature formula as a rigorous method for mean and variance estimation involving arbitrary input distributions and further extend its use to robust design optimization. One dimensional Gauss-type quadrature formula are constructed from the input probability distributions and utilized in the construction of multidimensional quadrature formula such as the tensor product quadrature (TPQ) formula and the univariate dimension reduction (UDR) method. To improve the efficiency of using it for robust design optimization, a semi-analytic design sensitivity analysis with respect to the statistical moments is proposed. The proposed approach is applied to a simple bench mark problems and robust topology optimization of structures considering various types of uncertainty.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.229-240
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• 2002

Quantum mechanical calculation is performed for the $O(^1D)$ + HCl ${\rightarrow}$OH + Cl reaction using Reactive Infinite Order Sudden Approximation. Shifting approximation is also employed for the l ${\neq}$ 0 partial wave contributions. Various dynamical quantities are calculated and compared with available experimental results and quasiclassical trajectory results. Vibrational distributions agree well with experimental results i.e. product states mostly populated at $v_f$ = 3, 4. Our results also show small peak at $v_f$ = 0, which indicates bimodal vibrational distribution. The results show two significant broad peaks in ${\gamma}_i$ dependence of the cross section, one is at ${\gamma}_i$ = $15^{\circ}-35^{\circ}$ and the another is at ${\gamma}_i$= $55^{\circ}-75^{\circ}$ which can be explained as steric effects. At smaller gi, the distribution is peaked only at higher state ($v_f$ = 3, 4) while at the larger gi, both lower state ($v_f$ = 0) and higher state ($v_f$ = 3, 4) are significantly populated. Such two competing contributions (smaller and larger ${\gamma}_i$) result in the bimodal distribution. From these points we suggest two mechanisms underlying in current reaction system: one is that reaction occurs in a direct way, while the another is that reaction occurs in a indirect way.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.5
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• pp.709-718
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• 2010

This paper deals with two contents: first, distributions of plate slenderness ratios, stiffened plate slenderness ratios, and stiffener slenderness ratios, which include dimensions and material variables of stiffened plates, of stiffened plates of large-sized in-service vessels, and, second, comparison of compressive strengths. The investigated vessels consist of 59 tankers, 49 bulkers, 28 product carriers, 15 container carriers, and 12 multi-purpose vessels. The tankers are ranged from handymax class to VLCC and larger than Suezmax class. The sizes of the bulkers are 20K to 200K deadweight. The maximum size of containers is less than 5000TEU class. Two parameters for normal distributions of the slenderness ratios (mean and standard deviation) are suggested and probable ranges of the slenderness ratios are also graphically presented. The ultimate strengths of the stiffened plates are presented using the various simplified formulas and nonlinear FEAs. As well, average compressive strength curves, which are necessary for the estimation of the hull girder moment capacities, are proposed. It is proved that formulas for stiffened plates in CSR overestimate slightly in overall average strain range. Mode5 formula (plate buckling mode) in CSR show unreasonably conservative results with respect to the ultimate strengths rather than post-ultimate average compressive strengths.