• Korean Journal of Computational Design and Engineering
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• v.14 no.2
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• pp.96-104
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• 2009

It gradually becomes important to study on how to efficiently integrate and manage plant lifecycle data such as 2D schematic and 3D solid data, logical configuration data, and equipment specifications data. From this point of view, converting plant design data from various systems into neutral data independent from any commercial systems is one of important technologies for the operation and management of plants which usually have a very long period of life. In order to achieve this goal, a neutral model for efficient integration and management of plant data was defined. After schema mapping between one of specification-driven plant design systems and the neutral model was performed, a plant data translator is also implemented according to the mapping result. Finally, by experiments with nuclear power plant design, the feasibility of the translator was demonstrated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.59-70
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• 2020

Three-dimensional (3D) design data is used for various purposes throughout the life cycle of a plant construction project. Plant 3D CAD systems support 3D modeling based on specs-catalogs, which contain data that are used for different purposes such as design, procurement, production, and handover. Therefore, it is important to share the spec-catalog data in the 3D design model with other application systems. Sharing this data thus requires a system that extracts spec-catalog data from plant 3D CAD systems and converts them into neutral model data. In this paper, we analyze equipment spec-catalog data of plant 3D CAD systems and, based on these analyses, define the data structure for neutral spec-catalog data. We subsequently propose a procedure that translates native spec-catalog data to neutral model data and develop a prototype system that performs this operation. The proposed method is then experimentally validated for the test spec-catalog data.

• Honam Mathematical Journal
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• v.45 no.3
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• pp.433-456
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• 2023

This paper deals with differentiability of solutions of neutral stochastic differential equations with respect to the initial data in the G-framework. Since the initial data belongs to the space BC ([-r, 0] ; ℝⁿ) of bounded continuous ℝⁿ-valued functions defined on [-r, 0] (r > 0), the derivative belongs to the Banach space 𝓛_BC (ℝⁿ) of linear bounded operators from BC ([-r, 0] ; ℝⁿ) to ℝⁿ. We give the neutral stochastic differential equation of the derivative. In addition, we exhibit two examples confirming the accuracy of the obtained results.

• KIEAE Journal
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• v.16 no.5
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• pp.29-37
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• 2016

Purpose: Indoor thermal comfort can be identified by combination of temperature, humidity, and air flow, etc. However, most thermal indexes in regard to thermal comfort are temperature dominant since it has been considered as a significant factor affecting to indoor thermal comfort The purposes of this study are to investigate indoor neutral temperature range of young Koreans with humidity perception, and to introduce a neutral temperature for temperature preference as well as temperature sensation in order to define the neutral temperature range chosen by occupants. It could be used as basic data for heating and cooling. Method: 26 research participants volunteered in 7 thermal conditions ($18^{\circ}C$ RH 30%, $18^{\circ}C$ RH 60%, $24^{\circ}C$ RH 30%, $24^{\circ}C$ RH 40%, $24^{\circ}C$ RH 60%, $30^{\circ}C$ RH 30%, $30^{\circ}C$ RH 60%) and completed subjective assessment in regard to temperature/humidity sensation and preference twice per condition in an indoor environmental chamber. Result: In RH 30%, sensation neutral temperature was $25.1^{\circ}C$ for men and $27.0^{\circ}C$ for women, and preference neutral temperature was $25.5^{\circ}C$ for men and $27.8^{\circ}C$ for women. In RH 60%, sensation neutral temperature was $23.6^{\circ}C$ for men and $25.9^{\circ}C$ for women, and preference neutral temperature was $23.4^{\circ}C$ for men and $26.3^{\circ}C$ for women. Neutral temperature increased with increasing relative humidity. Women were sensitive to humidity changes. Men expressed humidity changes as temperature variations. In most conditions, preference neutral temperatures were higher than sensation neutral temperatures, however, the preference neutral temperature for men in humid condition was lower than the sensation neutral temperature.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.195-196
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• 2008

This paper presents the stability analysis and design for a sampled-data fuzzy control system with neutral type of time delay. The sampling activity and neutral type of time delay will complicate the nonlinear system dynamics. And it make the stability analysis much more difficult than that for a continuous-time fuzzy control system. Based on the fuzzy control approach, linear matrix inequality (LMI)-based stability conditions are derived to guarantee the neutral T-S fuzzy system stability. Finally, an example is provided to illustrate the effectiveness of the proposed approach.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.79-84
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• 2004

In this study, a robot welding programming system is developed for gantry-type robot using a neutral CAD data format. The system automatically extracts welding line data from tile CAD model represented in IGES format and generates a robot program based on the weld line extracted. The welding program is simulated jar verification by using IGRlP, a virtual manufacturing solution. The robot welding programming system is demonstrated with a simple example.

• Korean Journal of Computational Design and Engineering
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• v.12 no.1
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• pp.74-85
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• 2007

During the lifecycle of a nuclear power plant many organizations are involved in KOREA. Korea Plant Engineering Co. (KOPEC) participates in the design stage, Korea Hydraulic and Nuclear Power (KHNP) operates and manages all nuclear power plants in KOREA, Dusan Heavy Industries manufactures the main equipment, and a construction company constructs the plant. Even though each organization has a digital data management system inside and obtains a certain level of automation, data sharing among organizations is poor. KHNP gets drawing and technical specifications from KOPEC in the form of paper. It results in manual re-work of definition and there are potential errors in the process. A data warehouse based on a neutral model has been constructed in order to make an information bridge between design and O&M phases. GPM(generic product model), a data model from Hitachi, Japan is addressed and extended in this study. GPM has a similar architecture with ISO 15926 "life cycle data for process plant". The extension is oriented to nuclear power plants. This paper introduces some of implementation results: 1) 2D piping and instrument diagram (P&ID) and 3D CAD model exchanges and their visualization; 2) Interface between GPM-based data warehouse and KHNP ERP system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.1-9
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• 2020

In highly complex EPC(engineering, procurement, construction)-based manufacturing processes such as shipbuilding and marine plants, it is essential to prepare a way to enable organic working at the site referring to each other's detailed working data for collaboration between partner companies. However, companies cannot share the progress of the sites including working information in real-time due to the use of SW unique to each company and the complex site management system. As a result, the construction process is delayed, and resources are used inefficiently. This study developed a neutral data generation algorithm that can apply the working information in various file formats to a collaborative manufacturing process. In addition, this study verified the accuracy of the algorithm by applying the developed algorithm to the manufacturing process of piping in shipbuilding and marine plants, developing the SW for visualization of working information using the generated neutral data, and comparing the coordinate, shape & dimension and the kind, number, and spec. of BOM. The result confirmed that the accuracy of the coordinate of the neutral data was 99%, and that of the shape & dimension of the neutral data and BOM Spec. was both 100%. It is thought that this study can be used for overcoming the restrictions in information sharing due to the development of informatization at companies and maximizing the share of working file information in a complex manufacturing process.

• The Korean Journal of Applied Statistics
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• v.25 no.5
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• pp.757-773
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• 2012

Traditional value at risk(S-VaR) has a difficulity in predicting the future risk of financial asset prices since S-VaR is a backward looking measure based on the historical data of the underlying asset prices. In order to resolve the deficiency of S-VaR, an economic value at risk(E-VaR) using the risk neutral probability distributions is suggested since E-VaR is a forward looking measure based on the option price data. In this study E-VaR is estimated by assuming the generalized gamma distribution(GGD) as risk neutral density function which is implied in the option. The estimated E-VaR with GGD was compared with E-VaR estimates under the Black-Scholes model, two-lognormal mixture distribution, generalized extreme value distribution and S-VaR estimates under the normal distribution and GARCH(1, 1) model, respectively. The option market data of the KOSPI 200 index are used in order to compare the performances of the above VaR estimates. The results of the empirical analysis show that GGD seems to have a tendency to estimate VaR conservatively; however, GGD is superior to other models in the overall sense.

• Korea-Australia Rheology Journal
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• v.19 no.2
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• pp.51-59
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• 2007

A polyelectrolyte chain confined in a slit nanochannel exhibits a structural transition from the one in free space. In this paper, the effect of the long-range electrostatic interactions between the xanthan polyelectrolyte and the slit wall on the confined xanthan conformation is investigated via the Brownian dynamics simulation. A neutral and two negatively charged surfaces of polydimethylsiloxane (PDMS) and glass are combined to make four kinds of slit channels with different charge characteristics: i) neutral-neutral, ii) glass-glass, iii) neutral-PDMS and iv) neutral-glass walls. Their walls are characterized by uniform surface charge densities determined from experimental data of zeta potential. Both the nonmonotonic chain size variation and the loss of long-range bond vector correlation, previously observed under confinement in the PDMS-PDMS slit, are also found in the neutral slit, demonstrating the nonelectrostatic origin of such crossover behaviors. As expected, the effect of wall charges is negligible at sufficiently high medium ionic strength of 100mM but it becomes significant in the opposite limit of 0.01mM. In the latter case, the high charge density of glass walls strengthens the effective confinement of a negatively charged polyelectrolyte and produces a xanthan structure comparable to that confined in a much narrower neutral slit. The obtained structural data suggest the possibility of controlling the structure of confined polyelectrolytes by the modification of surface charge characteristics of micro/nanofluidic devices in combination with the adjustment of the medium ionic strength.