• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.1020-1028
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• 2012

This work compares various models for geminate reversible diffusion influenced reactions. The commonly utilized contact reactivity model (an extension of the Collins-Kimball radiation boundary condition) is augmented here by a volume reactivity model, which extends the celebrated Feynman-Kac equation for irreversible depletion within a reaction sphere. We obtain the exact analytic solution in Laplace space for an initially bound pair, which can dissociate, diffuse or undergo "sticky" recombination. We show that the same expression for the binding probability holds also for "mixed" reaction products. Two different derivations are pursued, yielding seemingly different expressions, which nevertheless coincide numerically. These binding probabilities and their Laplace transforms are compared graphically with those from the contact reactivity model and a previously suggested coarse grained approximation. Mathematically, all these Laplace transforms conform to a single generic equation, in which different reactionless Green's functions, g(s), are incorporated. In most of parameter space the sensitivity to g(s) is not large, so that the binding probabilities for the volume and contact reactivity models are rather similar.

• International Journal of High-Rise Buildings
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• v.4 no.4
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• pp.311-318
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• 2015

The ASHRAE Design Guide for Tall, Supertall and Megatall Building Systems was produced in collaboration with the CTBUH. The design guide outlines various tall building mechanical systems that are presently being designed or are planned for the future. Tall commercial buildings in particular present a series of design problems that set them apart from other functions. The Design Guide will be of interest to owners, architects, structural engineers, mechanical engineers, electrical engineers and other specialized engineers and consultants. This design guide addresses design issues for tall commercial buildings, which are very often mixed-use, and commonly consist of low level retail, office floors, residential units, and hotel uses.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.422-429
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• 2001

A two dimensional hierarchical elements are investigated for a use on the incompressible flow computation. The construction of hierarchical elements are explained through the tensor product of 1-D hierarchical functions, and a systematic treatment of essential boundary values has been developed for the degrees of freedom corresponding to higher order terms. The numerical study for the poisson problem showed that the present scheme can increase the convergence and accuracy of finite element solutions, and can be more efficient than the standard first order with many elements. Also, for Stokes and cavity flow cases, solutions from hierarchical elements showed better resolutions and future promises for higher order solutions.

• The Journal of Information Systems
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• v.21 no.3
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• pp.45-70
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• 2012

Based on the usage levels of target costing systems(TCS) and information technology (IT) infrastructure, this study aims to develop a framework useful for classifying four types of knowledge management(KM) strategies in manufacturing firms: process-oriented, product-oriented, mixed and negative. We adopted a multi-methodological approach by mixing both qualitative and quantitative methods. Before developing a framework, through a case study of the H Motor Company in Korea, this paper investigated and showed the functions of TCS in the management of tacit knowledge. The results from the case study indicated that with the use of TCS, a firm can create, transfer, and share diverse kinds of tacit knowledge among employees for the facilitation of process innovation. We also empirically confirmed the four types of KM strategies, and demonstrated the characteristics(i.e., size, total sales, age, and knowledge intensity) of the organizations adopting each strategy.

• ETRI Journal
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• v.30 no.6
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• pp.757-764
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• 2008

In this paper, we present a design evaluation system with visualization and interaction of mobile devices using virtual-reality-based prototypes which can be used to easily change design parameters and simulate embedded software. To evaluate and predict affective-engineering-based design preferences for mobile devices under a virtual environment, we have developed a high quality visualization platform which creates images that look similar to real mobile devices in addition to real-time simulation of realistic motions and functions of mobile devices. To support a quantitative usability test scenario for external design shape, we also have built a system which consists of a mixed-reality-based testing platform for measuring hand load.

• Journal of applied mathematics & informatics
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• v.32 no.5_6
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• pp.721-736
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• 2014

We consider the equation ${\Delta}_mu=p(x)u^{\alpha}+q(x)u^{\beta}$ on $R^N(N{\geq}2)$, where p, q are nonnegative continuous functions and 0 < ${\alpha}{\leq}{\beta}$. Under several hypotheses on p(x) and q(x), we obtain existence and nonexistence of blow-up solutions both for the superlinear and sublinear cases. Existence and nonexistence of entire bounded solutions are established as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2312-2321
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• 2002

The first-order least-squares meshfree method for linear elasticity is presented. The conventional and the compatibility-imposed least-squares formulations are studied on the convergence behavior of the solution and the robustness to integration error. Since the least-squares formulation is a type of mixed formulation and induces positive-definite system matrix, by using shape functions of same order for both primal and dual variables, higher rate of convergence is obtained for dual variables than Galerkin formulation. Numerical examples also show that the presented formulations do not exhibit any volumetric locking for the incompressible materials.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.993-1002
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• 2008

Correlated responses have been widely analyzed since Liang and Zeger (1986) introduced the famous Generalized Estimating Equations(GEE). However, their variance functions were restricted to known quantifies multiplied by scale parameter. In so many industries and academic/research fields, power-of-the-mean variance function is one of the common variance function. We suggest GEE-type pseudolikelihood estimation based on the power-of-the-mean variance using existing software and investigate it's efficiency for different working correlation matrices.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.54-58
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• 1997

Spasmodic dysphonia is an uncommon and poorly understood disorder of motor control of laryngeal speech. We analysed 88 patients with spasmodic dysphonia, using chart review. These patients had historical information evaluated for age of onset(mean 39.2 years), duration of symptoms(mean 8.8 years), sex(4.2 : 1 female to male) family history(positive in 16.7%), and primary(84.8%) and secondary(15.2%) etiology : neurological evaluation for other dystonic involvement(40.7%). Eighty-three patients(94.3%) had adductor type of spasmodic dysphonia and 4 patients were abductor type and 1 patient was mixed type. All patients had normal thyroid and parathyroid functions and among 46cases, 8 patients had abnormal brain MRI finding. seventeen patients were evaluated by auditory brainstem response parameters. four out of the 17 patiemts had prolonged wave Ⅰ-Ⅴ interpeak latency.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.207-214
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• 2005

Productivity and quality stability are very important competitive factors in PCB manufacturing lines that process the multiple types of products with the mixed process flows under frequent order information changes. MES is an appropriate IT solution to solve these problems in the medium-sized PCB manufacturing company. This paper introduces the MES development and its effects for a medium-sized PCB manufacturing company. The main functions of an implemented MES are delivery simulation, production scheduling, and production process monitoring. Productivity are improved up to $10{\sim}20%$ and manufacturing lead times per order are shortened up to 2 days according to the manufacturing scenarios.