• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.7
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• pp.637-646
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• 2001

VOC(Volatile Organic Compound) removal characteristics in continuous flow reactors have been numerically investigated. The photocatalytic reaction have been simulated with the binding constant and the reaction rate constant obtained from experimental data for the constant-volume batch reactor, and then VOC abatement in continuous flow reactors with the same conditions as those of batch reactor has been analyzed. The standard 4\kappa-\varepsilon$ model and mass conservation equation have been employed for numerical calculation, and heterogeneous reaction rate has been used in terms of the boundary condition of the conservation equation. in the case of the continuous flow reactor, reaction characteristics have been estimated with various inlet velocities and with different number of baffles. The result shows that the concentration distribution and flow patterns are strongly affected by the inlet velocity, and that with the increased inlet velocity, VOC removal rate is increased, while removal efficiency is decreased. This result may be useful in the design of reactors with improved VOC removal efficiency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.2
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• pp.267-278
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• 1996

Steady, laminar, forced convection flow and heat transfer in the entrance region of an internally finned circular duct with a finite thermal conductivity has been analyzed numerically. The problem under investigation is a three-dimensional boundary layer problem, and is solved by employing a marching-type procedure which involves solution of a series of 2-dimensional elliptic problems in the cross-stream plane. Two types of inlet hydrodynamic conditions are considered : (a) uniform velocity flow and (b) fully developed flow. From the above inlet conditions, the effects of the fin height(h), fin number(N) and conductivity ratio($k_r$) on the flow and thermal characteristics are investigated. The numerical results show that the height and number of fins, and ratio of the solid to fluid thermal conductivity have pronounced effect on the solution. Considering pressure drop, optimized dimensionless fin height is 0.4.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.238-244
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• 2008

A numerical and experimental studies are carried out to investigate the heat transfer characteristics of 5kWth dish-type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical simulation. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Using the numerical model, the heat transfer characteristics of volumetric air receiver for dish-type solar thermal systems are known and the thermal performance of the receiver can be estimated.

• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.2
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• pp.43-52
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• 2013

This study aims to theoretically examine the educational and living elements that are needed for social education in the school system and suggest an approach to apply this result to the environmental aspects of the space in schools. To do this, characteristics of space in exemplary middle school oversee were analyzed. Also, the characteristics and status of the school space environment that foster socialization were examined. In order to increase students' social skills, the following community space should be considered. 1) teaching and learning spaces facilitating a variety of teaching methods, such as lecture, discussion, seminar classes, 2) open-spaces for communication among students, such as home base, hall, library, museum, and restaurant, 3) open-spaces for STEM education, 4) transparent windows located in the boundary wall between classrooms and hallways, 5) a large performance stage for presentation of student activities and experiences, 6) smart-learning spaces for fluent ICT system in classes and in public spaces, 7) restaurants and libraries located in the middle space of the school, and 8) ecological environments for student learning.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.50-57
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• 2005

We present a simple and effective method of face and facial feature detection under pose variation of user face in complex background for the human-robot interaction. Our approach is a flexible method that can be performed in both color and gray facial image and is also feasible for detecting facial features in quasi real-time. Based on the characteristics of the intensity of neighborhood area of facial features, new directional template for facial feature is defined. From applying this template to input facial image, novel edge-like blob map (EBM) with multiple intensity strengths is constructed. Regardless of color information of input image, using this map and conditions for facial characteristics, we show that the locations of face and its features - i.e., two eyes and a mouth-can be successfully estimated. Without the information of facial area boundary, final candidate face region is determined by both obtained locations of facial features and weighted correlation values with standard facial templates. Experimental results from many color images and well-known gray level face database images authorize the usefulness of proposed algorithm.

• Journal of Korean Academy of Nursing
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• v.39 no.2
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• pp.237-248
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• 2009

Purpose: The purpose of this study was to investigate the experience of urinary incontinence (UI) for elderly Korean women using a narrative approach. Methods: The data were collected using individual in-depth interviews with 15 communitydwelling elderly women who had UI for at least 1 yr. The narratives of the life stories of these women were analyzed from the actor’s perspective, motivation and purpose of actions, and action toward goal achievement. Also the narratives on UI were analyzed according to cognition, behavior, and evaluation of UI. Results: Three major types of the life stories emerged from the analysis. First, the conquest narrative type reflects active characteristics of narrators within the circumstances of the sociocultural context. Second, the patience narrative is characterized as having flexibility between self determination for goal achievement and the boundary of the sociocultural context. Lastly, the compliance narrative reflected characteristics of narrators who easily adapt their way of life to circumstances. In terms of UI, the narrators in all three types lacked awareness of UI as an illness condition. Three different reasons are specifically identified according to the narrative types. Conclusion: The results of this study indicate that the concept and the illness behaviors related to UI in elderly Korean women with UI were closely related to the way of women's lives within the sociocultural and historical context.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.187-194
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• 2006

Generally, earthquake-resistant structural systems have to ensure the sufficient stiffness and ductility for stability In this paper, the spatial structures are applied an isolation system to boundary parts between roof systems and sub-structures. So, it is necessary to examine the characteristics of dynamic behaviors of spatial structures governed by higher modes rather than lower modes different from the cases of high-rise buildings. The objectives of this paper are to develop the equivalent lumped mass model to simplify an analytical processes and to investigate the dynamic behaviors of roof systems according to the mass and stiffness of sub-structures as a fundamental study of performance design for the spatial structures.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.1
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• pp.43-57
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• 1999

The fluid flow and heat transfer in a thin liquid film are investigated numerically. The flow Is assumed to be two-dimensional laminar and surface tension is considered. The most important characteristics of this flow is the existence of a hydraulic jump through which the flow undergoes very sharp and discontinuous change. Arbitrary Lagrangian-Eulerian(ALE) method is used to describe moving free boundary and a modified SIMPLE algorithm based on streamline upwind Petrov-Galerkin(SUPG) finite element method is used for time marching iterative solution. The numerical results obtained by solving unsteady full Navier-Stokes equations are presented for planar and radial flows subject to constant wall temperature or constant wall heat flux, and compared with available experimental data. It Is discussed systematically how the inlet Reynolds and Froude numbers and surface tension affect the formation of a hydraulic jump. In particular, the effect of temperature dependent fluid properties is also discussed.

• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.117-120
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• 2005

This study was conducted to estimate population size and investigate habitat characteristics for the conservation and management of Amur goral Nemorhaedus caudatus raddeanus in DMZ (Demilitarized Zone) of Gangwon Province in South Korea from November 2003 to May 2004. The Amur gorals counting were carried out by assistance of military soldiers who guards the southern boundary of DMZ. Four hundred sixty individuals were estimated as total population size in DMZ of Gangwon Province. Deciduous forest, rocky area and coniferous forest were dominant land cover types in habitat of Amur goral. DMZ and its vicinity of Gangwon Province are very important areas for the conservation of this species. It is needed to establish management plan for the conservation of Amur goral and their habitats in DMZ.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.738-743
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• 2004

The microwave dielectric properties and their related structural characteristics in solid solutions of (1-x) $Ba(Mg_{1/3}Nb_{2/3})O_3$ -x $La(Mg_{2/3}Nb_{1/3})O_3$ (BLMN) have been investigated by measuring the dielectric constant${\varepsilon}r)$, Q value and temperature coefficient of resonant frequency$({\tau}f)$ and by observing the crystal structure using high resolution transmission electron microscopy (HRTEM). Microwave dielectric properties showed characteristic features for specific composition. Dielectric constant$({\varepsilon}r)$ showed maximum value at the composition which corresponds to the phase boundary between 1:2 ordered and 1:1 ordered structure. The increase in ${\varepsilon}_r$ may be caused by the rattling of ions by incorporating smaller ions and the disordered structure. The variation of temperature coefficient of resonant frequency${{\tau}_f)$ was investigated in terms of oxygen octahedra tilting.