• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.130-137
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• 2010

Due to test facility and specialty, it is physically difficult to conduct the modal tests of large-sized structures such as truck, bus and airplane. So, in case of a large-sized truck, the mode analysis on a full vehicle model comprised of reliable cabin, frame, and deck has been generally performed. However, the reliability of overall vibrational characteristics of the analytic model has not been fairly guaranteed by the testified models of each subsystem owing to the existence of cab suspension and the nonlinear mounting between a chassis frame and a special deck system. In this paper, a method to find out the modal characteristics of a large-sized military truck is presented. New modal test equipment is developed to set the boundary conditions of three military truck variants as close as a free-free condition. And the mode analysis method using coupled structure and dynamic models is established to consider the above-mentioned dynamic non-linearities of the vehicle itself. The usefulness of the suggested method is verified by comparing with the modal test results. Finally, the modal parameters of the final variant are extracted using the proved analytic method.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.63-70
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• 2010

The purpose of this paper is to propose a methodology that can measure the combat effectiveness of attack helicopter which Korea army will be operating in the near future. To measure the combat effectiveness, firstly, we use a wargame model, AAsim (Army Aviation simulation), as a analytic simulation model which is used to analyze DOTMLPF and operation in army aviation field, secondly we use an Analytic Hierarchy Process by opinion of experts. For simulation and AHP, we consider anti armored corps operation reflecting attack helicopter's combat effectiveness. As a result of this study, the combat effectiveness per each attack helicopter can be measured and this combat effectiveness is useful for reasonable decision making such as selection helicopter type, quantity when acquiring new weapon system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.90-97
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• 2002

Wall slip models are essential to the study of nonequilibrium gas transport in rarefied and microscale condition that can be found in gas flows associated with aerospace vehicle, propulsion system, and MEMS. The Maxwell slip model has been used for this type of problem, but it has difficulty in defining the so-called accommodation coefficient and has not been very effective in numerical implementation. In the present study, on the basis of Langmuir's theory of the adsorption of gases on metals, a physical slip model is developed. The concept of the accommodation coefficient and the difference of gas particles are clearly explained in the new model. It turned out that the Langmuir model recovers the Maxwell model in the first-order approximation. The new models are also applied to various situations including internal flow in a microchannel. Issues of validation of models are treated by comparing analytic results with experiment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.78-86
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• 2017

The new businesses started by the companies usually results in being unsuccessful. The main reasons for that are either aiming targeting wrong customers, unsatisfaction of customers' requesting quality standards, or taking wrong actions against the competitors in the market. Therefore, companies should aim the targets for the newly developing products based on the fulfilling values for the customers when they start the new businesses, and should take good cares for risk managements at the each step of the new business to prevent the failure in advance. In addition to that, the companies starting new businesses not only need to take the customers attributes (CA) into account, but they also should apply the new technologies as one system to initiate a new business to satisfy the basic wants of the customers. This article suggests the New Product Development Pursuing Model using the Indicative Planning methodology and the Quality Management tools. The New Product Development Pursuing Model would be completed by the following steps as below; 1. Drawing the CTQ (Critical To Quality) for setting up the new product development objectives by : i) using the VOC (Voice Of Customers) obtained by the QFD (Quality Function Deploypment) if the market is mature, ii) applying AHP (Analytic Hierarchy Process) to information in the QIS (Quality Information System) if the market is unmature to get enough need information of the customers. 2. Risk Management in NPD : The NPD pursuing model consisted of the IP (indicative planning) is suggested not by the process of top-down-way mandatory planning process, but by the tools used in the administrative science and economic fields, namely by governance. The companies could apply innovative methodology for new products development processes to fulfil the customers satisfaction in the fields, through the CA (Contingency Approach) of the NPD (New Product Development) process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10A
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• pp.941-949
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• 2007

By the newly emerging Network access technology, we face the new heterogeneous network environment. The required level of service quality and diversity are now multiplied by the increment of wireless service subscribers. Focusing on the co-existence of multiple access network technology and the complex service needs of users, the wireless service operators should present the stable service quality for every user. The service operators should build the new operation framework which combines the pre-established networks and newly adopted ones. Our problem is finding the optimal heterogeneous network operation framework. We suggest a market-based marginal cost function for evaluating the relative value of resource of each network and develop the whole new heterogeneous network operation framework.

• Journal of The Korean Association For Science Education
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• v.35 no.5
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• pp.919-929
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• 2015

This study aims to develop a modeling-based learning program about geologic structures and to reveal the relationship between the argumentation patterns and levels of students' mental models. Participants included 126 second grade high school students in four sessions of modeling-based learning regarding continental drift, oceanic ridges, transform faults, and characteristics of faults. A modeling-based learning program was implemented in two classes of the experimental group, and teacher-centered traditional classes were carried out for the other students in the comparison group. Science achievement scores and the distribution of students' mental models in experimental and comparison groups were quantitatively compared. The video-taped transcripts of five teams' argumentation were qualitatively analyzed based on the analytic framework developed in the study. The analytic framework for coding students' argumentation in the modeling-based learning was composed of five components of TAP and the corresponding components containing alternative concepts. The results suggest that the frequencies of causal two-dimensional model and cubic model were high in the experimental group, while the frequencies of simple two-dimensional model and simple cross sectional model were high in the comparison group. The higher the frequency of claims, an argumentation pattern was proven successful, and the level of mental model was higher. After the rebuttal was suggested, students observed the model again and claimed again according to new data. Therefore, the model could be confirmed as having a positive impact on students' argumentation process.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.421-426
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• 2024

The Analytic Hierarchy Process (AHP) converts people's judgment criteria into objective numerical values using pairwise comparisons. However, the need for an excessive number of pairwise comparisons poses a problem. To mitigate this issue, most existing studies have utilized the process separation approach. The method of process separation devised in this study is a "separation and integration approach," where 1) the standard AHP process is used for evaluating judgment criteria, and 2) the Multi-Attributive Utility Technique (MAUT) is applied for comparing alternatives. This AHP-MAUT Hybrid model was applied to a real analysis case, specifically analyzing the transportation choices of commuters between Bundang and Gangnam Station in Gyeonggi Province. The results showed that the computational process was reduced by 42.03% when applying the Hybrid model compared to using the AHP model alone. Furthermore, the choice results of residents using the Hybrid model were compared with those using the standard AHP. The consistency between the two models' choices was 82.1%, indicating a significant level of consistency. In conclusion, this study contributes by presenting a simpler, more convenient, yet equally effective Hybrid model as a new decision-support system alternative to AHP.

• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.183-193
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• 1986

Full scale HDR containment experiment series pointed out that the previous containment analysis models have a number of shortcomings. One of them is on the calculational model of short term (0~2sec) pressure difference. The pressure differences between subcompartments are dependent on the flow rate, fluid density, head loss coefficient, and flow area ratio. It, however, is not known that any of them is largely attributed to the disagreement of pressure difference between the measured and the calculated values. In this study, the head loss coefficients are expressed with another form to improve the analytic model. The pressure and the pressure difference are evaluated by using COMPARE code with new correlation, and the results show better agreements with experimental values for V.42 test, but overestimate the measured values for V, 43 and underestimate for V.44.

• Journal of Information Technology Applications and Management
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• v.20 no.1
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• pp.87-106
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• 2013

This study is to explore the airline network patterns of Incheon and Narita International Airports using passenger flight departure and arrival data of the two airports. The so-called Origin-Destination data is collected from the airports' websites and some of the important data items are flight number, city of origin, destination city, departure/arrival time, number of flights, and delay time. A snowflake schema dimensional model is proposed and implemented. Tableau Public, a well-known visual analytic tool, is used to connect the dimensional model and played an important role in navigating the data space to find interesting and visual patterns among corresponding airports and airlines. For the efficiency of analyzing this spacious data mart, data visualization method was used. Four types of visualization method proposed by Yau was used; visualizing patterns over time, visualizing proportions, visualizing relationships, and visualizing spatial relationships. The strength of connectivity of each flight segments is calculated to evaluate the degree of globalization of Seoul and Tokyo. We anticipate that various patterns and new findings produced by the data mart would provide airline managers, airport authorities, and policy makers in the field of travel and transportation with insightful information.

• Journal of Information Technology Applications and Management
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• v.19 no.3
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• pp.49-68
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• 2012

M&A (Merger and Acquisitions) is a standard corporate strategy frequently used by companies seeking to secure new growth engines and gain a solid foothold in their markets in order to become more globally competitive. To achieve the original goals of M&A, the two involved parties need to invest significant time and resources in integrating all aspects of the companies. A well-planned post-merger integration of information technology (IT PMI) by the two M&A parties is considered a crucial and difficult process because IT provides a fundamental infrastructure for integration. Considering various internal and external factors, the two parties normally formulate an IT PMI strategy. The many IT PMI strategies can be categorized into four major types: Renewal, Takeover, Standardization, and Synchronization. This study aims to develop a decision making model to help merger company and IT managers select the proper IT PMI strategy. More specifically, we identify key determinants that need to be considered when selecting a proper IT PMI strategy. The relative importance of each determinant is defined by analytic hierarchy process (AHP) analysis. Finally, this study evaluates each IT integration strategy under the identified determinants.