• Journal of Korean Institute of Industrial Engineers
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• v.31 no.2
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• pp.143-151
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• 2005

Information technology(IT) investment evaluation requires measurements from many perspectives. Except for the case of financial performance, these measurements mostly belong to the qualitative or intangible domain. The problem with IT investment evaluation lies in the fact that it is very difficult to define the qualitative properties against which to measure the performances. This paper addresses the issue of developing the set of performance indices, and defining the structural relationships between them, such that the IT investment evaluation can be done in a systematic, objective and comprehensive manner. We introduce the balanced scorecard strategy map as the backbone reference frame for the generation of performance indices and for the description of the relationships between them. Sample indices for evaluating projects from strategic perspectives are provided with a case example. A step by step follow through of the index generation process has been presented along with the case.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.551-559
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• 2005

Estimation of unknown signal parameters with sensor array measurements has been investigated quite extensively. Also, there has been in recent years an explosive increase in the number of mobile users in wireless cellular systems, thus contributing to growing levels of multi-user interference. To overcome this problem, application of adaptive antenna array techniques to further increase the channel capacity has been discussed. In this paper, a new model of locally scattered signals in the vicinity of mobiles is proposed by defining the mean steering vector and is manipulated mathematically for several distributions. Under this model an estimation method of the angle of arrival(AOA) is investigated based on a weighted subspace fitting(WSF) technique. Statistical analysis and simulations are also considered.

• Structural Engineering and Mechanics
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• v.23 no.1
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• pp.29-42
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• 2006

This paper describes the design scheme of the three-dimensional structures based on the concept of the cellular automata simulation. The cellular automata simulation is performed according to the local rule. In this paper, the local rule is derived in the mathematical formulation from the optimization problem. The cell density is taken as the design variable. Two objective functions are defined for reducing the total weight of the structure and obtaining the fully stressed structure. The constraint condition is defined for defining the local rule. The penalty function is defined from the objective functions and the constraint condition. Minimization of the penalty function with respect to the design parameter leads to the local rule. The derived rule is applied to the design of the three-dimensional structure first. The final structure can be obtained successfully. However, the computational cost is expensive. So, in order to reduce the computational cost, the material parameters $c_1$ and $c_2$ and the value of the cell rejection criterion (CRC) are changed. The results show that the computational cost depends on the parameters and the CRC value.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1619-1625
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• 2016

Recently, as the public interests about the 3D printing technology are increased, various kinds of 3D printers are being released. But, they are limited to use because they cannot fabricate an object which is larger than the printer's printing volume. To relieve this problem, we propose an interactive 3D mesh editing system for 3D printing the object that is larger than the printing volume. The proposed 3D editing system divides the input 3D mesh using the user's line drawings defining cutting planes and it attaches various connectors. The output meshes are guaranteed to fabricate without post-processing. The printed parts can be assembled using the connectors. Our proposed system has an advantage that it can be used easily by non-professional 3D printer users.

• Journal of Information Technology Services
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• v.14 no.4
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• pp.61-80
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• 2015

This paper has explored the analyzing and defining the core competencies of IT consultants who carry out IT consulting projects which desperately are needed by companies to survive in business competitions. Many companies have used IT consultants for their IT projects to achieve their project objectives. The problem of this is the results of IT projects carried out by IT consultants from the recognized consulting firms are quite often criticized by many clients who pay high price for hiring IT consultants. The purpose of this paper is that to weight of capability evaluation model for IT consultants. To define the capability model, I conducted the surveys from the IT professionals by the interview and e-mails. The result of this, this paper defines what core skills IT consultants should have to perform well when they carry out the IT projects. There are 6 major skills and 17 sub skills IT consultants should have in succeeding IT projects. 6 major skills are job competence skill, communication skill, business attitude, vocational values, job performance skill, leadership skill and related 17 sub skill are defined. With the capability evaluation model, the managers who are in the charge of incubating and enhancing the capability of IT consultants in the large corporation and also small, medium companies will utilize their companies' strength to get the advantage on the business competition.

• Bulletin of the Society of Naval Architects of Korea
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• v.13 no.4
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• pp.1-10
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• 1976

It is a well-known phenomenon that, in the case of vibrations of an elastic body in a fluid such as water, the presence of the surrounding fluid has the effect of lowering the natural frequencies of the vibration as compared with those in air or vacuum on account of the increased inertia, i.e. added mass. In this report, defining the mass increase factor as the ratio of added mass to vibration mass of the body in air, the author investigated the mass increased factor of an elastic plate vibrating in the fluid. It is assumed that the edges of the plate are simply supported, and that the surrounding fluid is an infinite ideal one. For the problem formulation the elliptical cylindrical coordinate system is adopted, so that a rectangular plate may be represented by a sheet degenerated from an elliptical cylinder. By virtue of the coordinate system adopted, plates which are chordwisely finite and lengthwisely contineous could directly be treated, but plates which are chordwisely finite in both directions could not be treated directly. For the latter, hence, plates which are chordwisely finite and lengthwisely semi-finite are investigated as an appropriate approximation. Some examples of the mass increase factor are numerically calculated for the fundamental mode and modes of zero or one nodal line in each direction with the range of the aspect ratio from 1 to 10 or more.

• Journal of Auto-vehicle Safety Association
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• v.13 no.2
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• pp.15-23
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• 2021

Even though the number of CO poisoning casualties caused by unintended idling for the vehicles equipped with keyless ignition systems is more than 70, the problem still remains unsolved and became social issue in the US, and Senates introduced the bill which urges NHSTA to make regulation for this accordingly. To meet market safety needs and the regulations, we decided to provide automatic shut-off system very soon. In this paper, we would like to describe how to validate vehicle shut-off timing including defining required tests and case selections considering vehicle condition, garage/room size and temperatures with several assumptions. We believe that safe implementation of the shut-off function is possible via this methodology and the results. As NHTSA must be interested in shut-off timing, the methodology can be enhanced and conclusions could be reflected highly in the future regulation in case we continue this study with NHTSA or any other 3-rd party institutes.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3488-3493
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• 2022

Accelerator driven subcritical systems have long been discussed as facilities which can be used for solving the nuclear waste problem. The physics of these systems is very different from conventional reactors and new techniques had to be developed for reactivity monitoring. One such technique is the Area Ratio Method which studies the response of a subcritical system upon insertion of a large number of neutron pulses. An issue associated with this technique is the spatial dependence of measured reactivity which is intrinsic to the sub criticality of the system since the reactor does not operate on the fundamental mode and measured reactivity depends on the detector position. This is generally addressed by defining Bell-Glasstone spatial correction factor. This factor upon multiplication with measured reactivity gives the correct reactivity which is independent of detector location. Monte Carlo Methods are used for evaluating these factors. This paper presents a complete three dimensional map of spatial correction factors for BRAHMMA subcritical system. In addition, the dataset obtained also helps in identifying detector locations where the correction factor is close to unity, thereby implying no correction if the detector is used at those locations.

• ETRI Journal
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• v.44 no.1
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• pp.85-93
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• 2022

We propose an efficient method for synthesizing mesh-based realistic computer-generated hologram (CGH). In a previous nonanalytic mesh-based CGH synthesis, the angular spectrum of the two-dimensional (2D) plane is calculated using the fast Fourier transform (FFT) with the same size as the resolution of the final hologram. Because FFT increases the computation time as the size of the input matrix increases, the previous method has a problem: The higher the resolution of the hologram, the greater the computational load, thereby delaying synthesis time. In this study, when calculating the angular spectrum of the 2D plane in mesh-based CGH synthesis, we propose a method to calculate the angular spectrum by defining the 2D plane with an arbitrary size smaller than the resolution of the final hologram. The resolution adjustment method reduces the computation time and can be applied to occlusion culling and texturing for the realistic effect of mesh-based CGH. We describe the principle, error analysis, application of realistic effect, and experimental results of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.253-258
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• 2021

With the 4th Industrial Revolution and the development of technology, markets of the VR&AR have increased. Also due to COVID-19 pandemic, demands for a digital environment were required because of physical space constraints. Firms are trying to solve this problem by using Metaverse platforms. However, with markets such as Metaverse, VR, AR, and Digital Twins are expanding, prior research on Metaverse definition or classification system is insufficient. Based on understanding VR&AR, Digital Twin, this study established a Industry-Service classification for Metaverse by defining Case studies on Metaverse and through prior research. And by Industry-Service classification for Metaverse this paper propose Metaverse Industry-Service Matrix to analyze the trend and possibility of Metaverse Platform