• Journal of the Korean Society of Systems Engineering
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• v.11 no.2
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• pp.61-73
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• 2015

The early-phase naval ship design demands requirements synthesis rather than design synthesis, which conducts engineering design for several domains on a detailed level. Requirements synthesis focuses on creating a balanced set of required operational capabilities satisfying user's needs and concept of operations. Requirements are evolved from capability based languages to function based language by statistical exploration and engineering design which are derived in the following order: concept alternative, concept baseline, initial baseline and functional baseline. The early-phase naval ship design process can be divided into three passes: concept definition, concept exploration and concept development. Main activities and outcomes in each pass are shortly presented. Concept definition is the first important step that produces a concept baseline through extensive design space exploration promptly. Design space exploration applies a statistical approach to explore design trends of existing ships and produce feasible design range corresponding to concept alternative. It further helps naval systems engineers and operational researchers by inducing useful responses to user and stakeholders' questions at a sufficient degree of confidence and success in the very early ship design. The focus of this paper is on the flow of design space exploration, and its application to a high-speed patrol craft. The views expressed in this paper are those of the authors, and do not reflect the official policy or rule of the Navy.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.1
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• pp.17-32
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• 2014

The trade-off studies in the concept development stage to assess the relative goodness of alternative systems concepts for AE (architect engineering) design for the Barge Mounted SMR (BMSMR) is introduced. With respect to design margin, system performance, schedule and risk, the design selection is cond ucted using the following characteristics; barge mobility, system safety under the natural disaster (seismic), power output, interfacing with the other system, and the additional supporting functions as desalination. There are three findings that should be remedied; deficiencies in the assumed characteristics of the system being modeled, deficiencies in the test model, and excessively stringent system requirements. This study is performed using systems engineering approach with trade off matrix method. In order to execute this work, concept development stage is divided into three (3) phases as NA (needs analysis), CE (concept exploration), and CD (concept definition).

• Journal of the Korean Society for information Management
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• v.19 no.1
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• pp.47-69
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• 2002

The concept based retrieval model has shown a higher performance than those of the simple matching function method or the P-norm retrieval method introduced to compensate the demerits of the Boolean retrieval model. However. it takes too long to create a semantic-net knowledge base, which is essential in concept exploration. In order to solve such demerits. a method was sought out by creating a distributed knowledge base by subjects to reduce construction time without hindering the performance of retrieval.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.15-22
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• 2021

The purpose of this study is to identify the factors that influence the nursing students' nurse image and professional self-concept on career exploration. This study was accomplished on 153 students in the 2nd, 3rd and 4th grades of the Department of Nursing Science at a college in area Y, and data were collected from July 1 to August 31, 2020 using a structured questionnaire. Measurement tools consisted of nurse image, professional self-concept, and career exploration behavior. Data processing was performed using the SPSS 22.0 program where general characteristics were analyzed by t-test, ANONA and post examination tests by Scheffe's test, using mean score, standard deviation, Pearson's correlation, and stepwise multiple regression. Nursing students' nurse image, professional self-concept, and career exploration behavior were all found to have significant positive correlations, and the most influential variable was professional self-concept. As for the total explanatory power of these variables, model 2 showed 25% explanatory power, which was increased by 2% compared to model 1. Based on this result, it is necessary to develop education and a career exploration action program which can improve the nurse image and professional self-concept.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.9-24
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• 2015

Construction industry faces a lot of inherent uncertainties and issues and the construction phase of nuclear power project is not free from this risk. This paper investigates promising methodologies to be used on nuclear power plant (NPP) construction schedule delay risk assessment by using entry level systems engineering approach. This study contains how the initial concept for the risk assessment methodology has been developed. In this point of view, this work structured on three main phases: needs analysis (NA), concept exploration (CE), and concept definition (CD) through systems engineering (SE) approach. Traditionally, the SE process is applied to technical development programs but this study opens up a new avenue that SE can also be successfully applied to the development and optimization of the risk assessment model. This study provides a rational and systematic process for developing and selecting the best risk assessment model. This paper selects analytic hierarchy process (AHP) method to assess NPP construction schedule delay risk for international project. As conclusion, the proposed concept and selected method can discriminate successfully and clearly among schedule delay risk assessment methods.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.1
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• pp.33-41
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• 2014

New design concept of Reactor Coolant System (RCS) including a reactor assembly for the SMR is introduced in this work. An exploration of new type of reactor that is advanced from proposed SMRs is performed by using systems engineering approach. In this point of view project structured on three main phases; needs analysis (NA), concept exploration (CE), and concept definition (CD). Main objectives as an output of the CE stage are a small size, low cost, shortening the schedule, and enhancing safety. The SMRs usually have a small size requirement. In order to meet the size requirement and to achieve a productivity, in other words, easiness to manufacture, this paper suggests an integrated PWR design concept through researching predecessors. Although the integrated PWR concept provides many advantages, it has disadvantages that composite of maintenance and a low availability problem. Therefore, this paper comes up with a run-to-fail design concept based on modular design to address the maintenance problem and to maximize the availability of SMRs as well as to be compatible with the overall-SMRs including Barge Mounted(BM)type.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.236-248
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• 2016

In this review, the basic concepts of geodetic coordinate system and map projection are explained to practitioners in exploration geophysicists to enhance the understanding of geographic and projected coordinate system. The fundamental elements such as earth ellipsoid, geoid, geocentric and geodetic latitudes, rhumb line, and great circle are dealt with in detail. The geocentric and geodetic coordinate systems are also summarized neatly, together with coordinate conversion formulae. In addition, the concept and technique for datum transforms between local and world datum are presented, with special emphasis on Korean Geodetic System.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.12
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• pp.877-888
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• 2022

Recently, as the CAPSTONE, a precursor mission for Lunar Gateway, was launched on a small launch vehicle for the purpose of demonstrating communications and navigation technology in the NRHO, large attention was brought to this event that enabled high-impact deep space mission using dedicated small launch vehicle and small spacecraft. In this study, we introduced the concept of a dual launch operation and examined the capability of the new concept in the exploration of the Moon, Mars and asteroid. It turned out a single launch is sufficient for the lunar low orbit mission up to around 247 kg, and the dual launch option can transport 215 kg and 183 kg to nearby destinations as such as Mars and astroid Apophis respectively.

• Geophysics and Geophysical Exploration
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• v.1 no.1
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• pp.43-48
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• 1998

Recently seismic tomography has been widely used to visualize subsurface structure for resource explorations and construction site evaluation. We studied a way to include fresnel zone concept in the conventional ray-based traveltime tomography. The algorithm developed uses the same order of computing time as the conventional traveltime to mography but incorporates the rigorous wavepath concept of wave-equation tomography. Some experiments to synthetic and real data show reasonable results compared to conventional ray-based traveltime tomography.

• Journal of the Korean School Mathematics Society
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• v.8 no.2
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• pp.203-222
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• 2005

The purpose of this study is to investigate students' understanding of functions based on concept image and concept definition suggested by Vinner, For the study a graphing calculator was provided as a tool for students to use for their exploration. Three students participated in the study using the qualitative research method to identify their processes of understanding functions. The student with previous experiences of the functions had various concept images about the functions and did not have many opportunities to modify their images because the student did not want to depend on the calculator. However, the student who did not have many chances to study about the functions before used the calculator effectively for developing the concept definition on the functions. The calculator played an important role in connecting different representations and finding relationships between these representations supported by dynamic exploration.