• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.101-108
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• 2004

A construction process consists of value adding activities and non-value adding activities, necessary or unnecessary. If construction personnel can eliminate inefficient and/or unnecessary activities within the process, they may have a great opportunity to improve their construction process. The Product Process Analysis (PPA) technique, which was developed in the manufacturing industry, can be applied for identifying wastes in the construction process and ultimately improving the process itself. It provides useful tools, such as a process chart worksheet and flow diagram, for mapping the flow of construction activities with predetermined standardized symbols. These tools make people understand the flow of activities more easily, identify value adding/non-value adding activities within the process, and areas where the process can be improved. The example applications of PPA are demonstrated in the paper through the case studies implemented on the construction process of structural steel. The results of case studies indicate that PPA technique was effective at identifying and removing wastes in the steel construction process. It is also found that PPA technique is more effective for improving highly repetitive construction processes.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.11
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• pp.1410-1416
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• 1999

This paper aims at investigating the operating-mode characteristics of two-module Thyristor Controlled Series Compensator (TCSC) as an equivalent of the multi-module TCSC in a simple three-phase power transmission system. The load flow program is developed to analyze the steady-state characteristics of two-module TCSC system and to find the thyristor firing angles for the required real power flow. The stability calculation program is developed with Poincare mapping theory. Simulation studies of the TCSC power transmission system using EMTP are performed to evaluate the transient characteristics of two-module TCSC as a real power flow controller and to rpove the results of the load flow calculation and the stability analysis. In the process of the study, the operating-mode characteristics of two-module TCSC are evaluated and compared to those of single-module TCSC.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.45-55
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• 2017

Release and fire/explosion tests of flammable gas are extremely dangerous. Furthermore, it is difficult to select the site where the experiment can be performed. In these reasons, gas flow analysis(CFD) has been used as much as possible. However, with the opening of the Energy Safety Empirical Research Center in Yeongwol-gun, Gangwon-do in October 2016, it was possible to conduct releases and detection tests of small scale combustible gas as well as large scale / high pressure / ultra low temperature experiments. In this study, LPG leaked after the calibration and placement of the sensor, the sensor detected LPG and the data were visualized as a contour map. And the differences between the actual release(28s, max 3.7[m]) and the analysis were analyzed compared to the FLACS analyzed under the same conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.287-294
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• 2007

A static aeroelastic analysis for supersonic aircraft wing equipped with external store under the wing lower surface is performed using computational fluid dynamics (CFD) and computational structural technology(CST) coupling methodology. Two mapping algorithms, which are the pressure mapping algorithm and the displacement mapping algorithm, are used for CFD/CST coupling. A three-dimensional unstructured Euler code and finite element analysis program are used to calculate the flow properties and the structural displacements, respectively. The coupling procedure is repeated in an iterative manner until a specified convergence criterion is satisfied. Static aeroelastic analysis for a typical supersonic flight wing is performed and final converged wing configuration is obtained after several iterations.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.18 no.1
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• pp.31-37
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• 2007

Objectives : A voxel based investigation of cerebral blood flow was conducted to identify functional differences during resting state between children with early-onset schizophrenia and normal controls. Methods : 19 children and adolescents with early-onset schizophrenia(8 boys and 11 girls, mean age $14.0{\pm}1.7$ years old) and 17 comparison children(13 boys and 4 girls, mean age $11.0{\pm}1.9$ years old) were examined by HMPAO-SPECT. The SPECT images were compared using statistical parametric mapping analyses, controlling for age and sex. Results : Increased cerebral blood flow in left medial and inferior frontal gyrus, right superior and middle frontal gyrus, both inferior temporal gyrus, and right cerebellar tonsil was found in children and adolescents with early-onset schizophrenia compared to control subjects. In addition, decreased cerebral blood flow in right thalamus, left posterior cingulate gyrus, right anterior cingulate gyrus and relatively wide areas from left medical frontal gyrus to superior parietal lobule were found in children and adolescents with early-onset schizophrenia compared to control subjects. Conclusion : The results of the current study provide additional evidences for brain areas involving the onset of schizophrenia in early age.

• Journal of the Korean Society of Combustion
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• v.8 no.3
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• pp.15-23
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• 2003

Partial quenching structure of turbulent diffusion flames in a turbulent mixing layer is investigated by the method of flame hole dynamics in order to develop a prediction model for turbulent flame lift off. The essence of flame hole dynamics is derivation of the random walk mapping, from the flame-edge theory, which governs expansion or contraction of flame holes initially created by local quenching events. The numerical simulation for flame hole dynamics is carried out in two stages. First, a direct numerical simulation is performed for constant-density fuel-air channel mixing layer to obtain the turbulent flow and mixing fields, from which a time series of two dimensional scalar dissipation rate array is extracted at a fixed virtual flame surface horizontally extending from the end of split plate to the downstream. Then, the Lagrangian simulation of the flame hole random walk mapping projected to the scalar dissipation rate array yields temporally evolving turbulent extinction process and its statistics on partial quenching characteristics. The statistical results exhibit that the chance of partial quenching is strongly influenced by the crossover scalar dissipation rate while almost unaffected by the iteration number of the mapping that can be regarded as a flame-edge speed.

• Journal of KIISE:Software and Applications
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• v.32 no.6
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• pp.486-501
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• 2005

XPDL is a XML-based language for process definition exchange that is proposed by WfMC. This paper propose a model which model XPDL document structure (Schema) using UML in order to define and to exchange workflow process, and make business flow understanding ease for inter-business cooperation. So, we define mapping rules in which map XPDL documents into UML class diagram and UML activity diagram. By these mapping rules, elements composing XPDL process meta-model are mapped into UML class diagram, and process activities are mapped into UML activity diagram. Also, we apply proposed mapping technique to model a workflow of (')Credit card state check system.(')

• Korea-Australia Rheology Journal
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• v.15 no.4
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• pp.197-208
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• 2003

Two measures of distributive mixing are examined: the standard deviation $\sigma$ and the maximum error E, among average concentrations of finite-sized samples. Curves of E versus sample size L are easily interpreted in terms of the size and intensity of the worst flaw in the mixture. E(L) is sensitive to the size of this flaw, regardless of the overall size of the mixture. The measures are used to study distributive mixing for time-periodic flows in a rectangular cavity, using the mapping method. Globally chaotic flows display a well-defined asymptotic behavior: E and $\sigma$ decrease exponentially with time, and the curves of E(L) and $\sigma$ (L) achieve a self-similar shape. This behavior is independent of the initial configuration of the fluids. Flows with large islands do not show self-similarity, and the final mixing result is strongly dependent on the initial fluid configuration.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.298-313
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• 2006

Six sigma is focused on quality improvement through variation reduction, while lean is on process flow improvement and lead time reduction by waste elimination. However, lean cannot bring a process under statistical control and six sigma alone cannot dramatically improve process speed. Lean six sigma was developed to achieve faster rate of improvement in customer satisfaction, cost, quality, process speed, and invested capital. In this paper we present the importance of using value stream mapping and suggest a guideline on how to integrate lean and six sigma by is proposed.

• Journal of Korean Society for Quality Management
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• v.32 no.4
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• pp.184-195
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• 2004

Current companies 집중 on how to operate and select projects to achieve the best result. 6sigma projects are chosen in the best suitable concept, which are solved by the 6Sigma experts according to the priority. And every project has to be launched not the view of individual management factors but the total factors, Big Y. Therefore, a process needs to be treated to connect the vital few factors in various processes to improve the yield, which is the main performance criteria in a manufacturing industry This report is to make the total optimization through the Vital-Few mapping between quality characteristics and process factors in a manufacturing line. Accordingly, it means to secure lower variance by making the CTP(Critical To Process) optimization and finally to improve the yield.