• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.22-30
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• 2021

The ship wake generated by rotation of the propeller yields changes of characteristics of sound wave such as attenuation and scattering. To develope a battle field environment simulator for military purposes, it is very important to understand acoustical properties of ship wake. Existing research results have limitations in direct application because they performed under simple conditions or model ships were applied. In this study, we developed a ship wake generation model based on the ship's geometric wake distribution theory. The model can provide spatial distribution and void fraction with various marine environments as well as ship size. Through the developed model, geometric distribution features of ship wake according to the ship's maneuvering conditions were successfully simulated. In addition, changes of the bubble void fraction with time at any location within the battle field environment were identified. Therefore, the developed model is expected to be used in the development of a simulator to measure the acoustic characteristics of the ship wake.

• Journal of Agricultural Extension & Community Development
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• v.13 no.1
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• pp.123-134
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• 2006

The purpose of this study was to establish the effective model for community-centered youth development in Korea. The research methods used the extensive review of related literatures and consultation with a panel of experts in this field. Based on the major results, the implications and suggestions were as follows. First, community youth development will need to provide the opportunities of competencies and a full complement of positive connections to youth activities. Second, communities promote to engage youth as partners with adults in the process of positive youth development. Third, youth development organizations operate to support the programs to prevent or treat specific problems in terms of community youth contexts. Finally, collaboration and network are necessarily required among youth, adults, home, school, organizations within the community.

• Korean Journal of Health Education and Promotion
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• v.27 no.2
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• pp.141-149
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• 2010

Objectives: This paper aims to compare the intervention development steps of the revised PRECEDE-PROCEED model and the Intervention Mapping model. Methods: Concepts and structure of the intervention development step of each model are reviewed with examples. Results: The revised PRECEDE-PROCEED model and the Intervention Mapping model share characteristics in intervention development in employing PRECEDE assessments, applying a social ecological framework and behavior theories for intervention building, emphasizing multi-interventions at multiple levels, and involving stakeholders and existing resources in intervention development. A detailed explanation of the intervention alignment and matrix building is provided with illustration of examples. Conclusion: Intervention development should not be done compartmentally but in line with other steps in a planning model to sustain the program logic. For successful application of planning models for intervention development, solid understanding of the models and behavior theories are required. Multisectoral collaboration is also critical for the successful application.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.485-499
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• 2014

Sharing Economy is the modern main item with ICT Development. Of course sharing economic item is the old and long run mainstream, but by the ICT technological development sharing economy is the fostering and affluent factors in the world economic growth. Though, in Korea, till now sharing economy is minimal, that will growth sharply. We can track various business models of sharing economy. Sharing economy is to buy use right not ownership. With the sharing economic business model wee can make also financial sharing model. In finance model we can divide two kind models. First, we can trace small size lending model with p2p type. And second, we can make financial information transaction model. But till now sharing economic system is not activated, because of many reasons. To activate, first we have to set law and various standards, and also government actively support many sharing economy firms and institutions. To catch up developed countries in the field of sharing economy we have to make aggressive and flexible rules and standards.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.554-560
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• 2019

In this study, after applying the finite failure NHPP Rayleigh distribution model and NHPP Inverse Rayleigh distribution model which are widely used in the field of software reliability to the software development cost model, the attributes of development cost and optimal release time were compared and analyzed. To analyze the attributes of software development cost, software failure time data was used, parametric estimation was applied to the maximum likelihood estimation method, and nonlinear equations were calculated using the bisection method. As a result, it was confirmed that Rayleigh model is relatively superior to Inverse Rayleigh model because software development cost is relatively low and software release time is also fast. Through this study, the development cost attributes of the Rayleigh model and the Inverse Rayleigh model without the existing research examples were newly analyzed. In addition, we expect that software developers will be able to use this study as a basic guideline for exploring software reliability improvement method and development cost attributes.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.06a
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• pp.31-35
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• 2003

In the late 1990s, ROK Army started developing a simulation model(ChangJo21) for division/corps level battle command training and finished it successfully. The CJ2l model provides realistic representation of Korean characteristics in doctrine, weapon systems, terrain, and climate etc. The successful development of CJ2l implanted us with confidence on high-technology model development and this has been our motive for development of JeonToo21 for battalion/regiment level battle command training and other war-game models like Hwarang21 (Rear Area Ops. Model) and Vision21 (Division Combat Analysis Model). Eventually, ROK Army was able to establish M&S system by echelons, from battalion to corps. Moreover interoperability between ROK-US simulation systems are on the progress. In this paper, we introduce recently developed 3 war-game simulation models and mention on the future directions of ROK Army Modeling & Simulation.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.4
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• pp.164-173
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• 2009

Automotive systems have tended to be equipped with many electronic contents to satisfy safety, comport, convenience, and entertainment services over the past years. As a result, the amount of vehicle embedded software in electrical/electronic(E/E) systems is steadily increasing to manage these requirements. This leads to the traditional, document-based software development in the vehicle embedded systems being increasingly displaced by a model-based development in order to reduce software development time and cost. Due to the application of model-based development, a great evolution is being realized in the aspect of efficiency, but the development is being made without sufficient testing. So, erroneous automotive embedded software may cause serious problems such as car accidents which relate to human safety. Therefore, efficient methods for model-based test and validation are needed to improve software reliability in the stage of embedded software development. This paper presents the model-based development and test method for AUTOSAR embedded software to improve its reliability and safety, and it is demonstrated based on the case study.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.1
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• pp.20-26
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• 2019

In this paper, we propose measurement based numerical resistivity model for low energy exploding foil initiator (LEEFI) of electronic safety and arming device(ESAD). A resistivity model describes a behavior of variable resistance in LEEFI by firing current. The previous resistivity model was based on high energy detonator applications as explosive bridge wire and exploding foil initiator. Therefore, to estimate the voltage, current, and burst time of LEEFI, a resistivity model suitable for LEEFI is needed. For the modeling of resistivity of LEEFI, we propose a specific action based equation which represents a behavior of LEEFI when firing current is applied. To verify the proposed model, we analyze a firing current transmission path to obtain parasitic impedance. We experimentally verify that the proposed resistivity model offers precise estimation for the behavior of variable resistance in LEEFI.

• Atmosphere
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• v.30 no.2
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• pp.141-154
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• 2020

Seasonal forecast is growing in demand, as it provides valuable information for decision making and potential to reduce impact on weather events. This study examines how operational climate prediction systems can be reliable, producing the probability forecast in seasonal scale. A reliability diagram was used, which is a tool for the reliability by comparing probabilities with the corresponding observed frequency. It is proposed for a method grading scales of 1-5 based on the reliability diagram to quantify the reliability. Probabilities are derived from ensemble members using hindcast data. The analysis is focused on skill for 2 m temperature and precipitation from climate prediction systems in KMA, UKMO, and ECMWF, NCEP and JMA. Five categorizations are found depending on variables, seasons and regions. The probability forecast for 2 m temperature can be relied on while that for precipitation is reliable only in few regions. The probabilistic skill in KMA and UKMO is comparable with ECMWF, and the reliabilities tend to increase as the ensemble size and hindcast period increasing.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.279-287
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• 2018

This study investigated applicability of the fast running model for damage assessment of underground structures by ground shock. For this reason, the fast running model that consists of two main models such as the ground shock generation and propagation model and the underground structural damage assessment model was developed. The ground shock generation and propagation model was programed using theoretical formula and empirical formula introduced in TM5-855-1(US army manual). The single degree of freedom model of structural components was utilized to predict structural dynamic displacements which are used as index to assess damage level of components. In order to confirm the feasibility of the developed fast running model, underground structural dynamic displacements estimated from the fast running model were compared to displacements obtained from the finite element analysis.