• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.183-186
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• 2015

Recently, the demand for the safety and the information delivery system in the ship increases. The deployment of the wireless sensor networks instead of using the built-in wired networks or the setup of the new wired networks is more desirable than the deployment of the wired networks in a ship after its final production since it can reduce the cost and the time of the brand new wired networks by deforming some of the internal structure of the ship. In this paper, the shipboard signal propagation measurement system based on the signature sequence-two way slave mode are designed and its measurement data are analysed after measuring the signal propagation characteristics. Consequently, it is expected that the reliable and cost-effective signal measurement system for the deployment of the shipboard wireless networks can be built.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.746-756
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• 2013

The emitter geolocation method using the time difference of arrival (TDOA) and the frequency difference of arrival (FDOA) has more accurate performance comparing to the single TDOA or FDOA based method. The estimation performance varies with the sensor paring strategies, the deployment and velocities of the sensors. Therefore, to establish effective strategy on the electronic warfare system, it is required to analyze the relation between the estimation accuracy and the operational condition of sensors. However, in the conventional non-iterative method, the restriction of the deployment of sensors and the reference sensor exists. Therefore, we derive the emitter geolocation method based on a Gauss-Newton method which is available to apply to any various sensor pairs and the deployment and velocities of the sensors. In addition, simulation results are included to compare the performance of geolocation method according to the used measurements: the combined TDOA/FDOA, TDOA, and FDOA. Also, we present that the combined TDOA/FDOA method outperforms over single TDOA or FDOA on the estimation accuracy with the CEP plane.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.10
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• pp.705-711
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• 2019

Dynamic behaviors of the deployable composite reflector antenna are numerically and experimentally investigated. Equations of the motion are formalized using Kane's equation by considering multibody systems with two degrees of freedom such as folding and twisting angles. To interpret structural deformations of the reflector antenna, the composite reflector is modeled using a beam model with the FSDT(First-order Shear Deformation Theory). To determine design parameters such as a torsional spring stiffness and a damping coefficient depending on deployment duration, an inverted pendulum model is simply applied. Based on the determined parameters, dynamic characteristics of the deployable reflector are investigated. In addition, its results are verified and compared through deployment tests using a gravity compensation device.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.28-39
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• 2022

With the development of small multicopter PAV (Personal Air Vehicle), it is necessary to develop safety-related devices for manned rotorcraft. In this study, we assumed that an external airbag can be installed in a small multicopter PAV, and using LS-DYNA's Airbag Folding Application, we performed a free-fall collision analysis by modeling the airbag shapes consisting or Roll, Zigzag, and Sigma. There was no significant difference in the final airbag deployment time of the three models. However, when it collides with the ground during deployment, the Sigma fold type external airbag had the fastest deployment speed, applying the most impact force to the PAV, while the Roll fold type external airbag applied the smallest impact force to the PAV.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.123-131
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• 2015

With a prospective of rapid deployment of IOT, a systematic approach to derive a business strategy for various possible scenarios of IOT applications is in great demand. In this paper, a conceptual framework that can be utilized for the purpose of assessing the market potential and of setting up an initial business strategy for IOT deployment is suggested. The framework consists of utilization of well-known value curve analysis, ecosystem analysis and house of quality tools. The value curve analysis is utilized to identify value-enhancing components of consumers as well as relative strengths of suppliers. The ecosystem analysis is used to identify relevant players of the supply chain and their mutual relationships. The house of quality is suitable for developing the initial business strategy of the supplier by converting consumer requirements identified by value curve analysis into technical requirements for the supplier. In this paper, we applied our proposed framework to two services that have high potentiality of being benefited by IOT: car-sharing service and telehealth service.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.246-262
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• 2023

The purpose of this study is to identify the major peacekeeping activities that the Korean armed forces has performed from the past to the present. To do this, we collected 692 press releases from the National Defense Daily over the past 20 years and performed topic modeling and social network analysis. As a result of topic modeling analysis, 112 major keywords and 8 topics were derived, and as a result of examining the Korean armed forces's peacekeeping activities based on the topics, 6 major activities and 2 related matters were identified. The six major activities were 'Northeast Asian defense cooperation', 'multinational force activities', 'civil operations', 'defense diplomacy', 'ceasefire monitoring group', and 'pro-Korean activities', and 'general troop deployment' related to troop deployment in general. Next, social network analysis was performed to examine the relationship between keywords and major keywords related to topic decision, and the keywords 'overseas', 'dispatch', and 'high level' were derived as key words in the network. This study is meaningful in that it first examined the topic of the Korean armed forces's peacekeeping activities over the past 20 years by applying big data techniques based on the National Defense Daily, an unstructured document. In addition, it is expected that the derived topics can be used as a basis for exploring the direction of development of Korea's peacekeeping activities in the future.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.95-108
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• 2005

The purpose of this study is to develop the ITS evaluation model using the Probabilistic Risk Analysis (PRA) methodology and to demonstrate the goodness-of-fit of the large ITS projects through the comparative analysis between DEA and PRA model. The results of this study are summarized below. First, the evaluation mode] using PRA with Monte-Carlo Simulation(MCS) and Latin-Hypercube Sampling(LHS) is developed and applied to one of ITS projects initiated by local government. The risk factors are categorized with cost, benefit and social-economic factors. Then, PDF(Probability Density Function) parameters of these factors are estimated. The log-normal distribution, beta distribution and triangular distribution are well fitted with the market and delivered price. The triangular and uniform distributions are valid in benefit data from the simulation analysis based on the several deployment scenarios. Second, the decision making rules for the risk analysis of projects for cost and economic feasibility study are suggested. The developed PRA model is applied for the Daejeon metropolitan ITS model deployment project to validate the model. The results of cost analysis shows that Deterministic Project Cost(DPC), Deterministic Total Project Cost(DTPC) is the biased percentile values of CDF produced by PRA model and this project need Contingency Budget(CB) because these values are turned out to be less than Target Value(TV;85% value), Also, this project has high risk of DTPC and DPC because the coefficient of variation(C.V) of DTPC and DPC are 4 and 15 which are less than that of DTPC(19-28) and DPC(22-107) in construction and transportation projects. The results of economic analysis shows that total system and subsystem of this project is in type II, which means the project is economically feasible with high risk. Third, the goodness-of-fit of PRA model is verified by comparing the differences of the results between PRA and DEA model. The difference of evaluation indices is up to 68% in maximum. Because of this, the deployment priority of ITS subsystems are changed in each mode1. In results. ITS evaluation model using PRA considering the project risk with the probability distribution is superior to DEA. It makes proper decision making and the risk factors estimated by PRA model can be controlled by risk management program suggested in this paper. Further research not only to build the database of deployment data but also to develop the methodologies estimating the ITS effects with PRA model is needed to broaden the usage of PRA model for the evaluation of ITS projects.

• The Journal of Society for e-Business Studies
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• v.13 no.3
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• pp.173-188
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• 2008

While many success stories are reported in the area of RFID applications, actual RFID deployments in industry are being realized a lot slower than expected. One of the main reasons for that is the lack of decision makers' understanding on the RFID ROI. In this research we drew a comprehensive list of cost and benefit items regarding RFID deployments especially for distribution and retail industry. In addition, we mapped these cost/benefit items to corresponding SCOR processes so that users can easily utilize the suggested cost-benefit analysis model when they want to improve their own processes using the RFID technology. The developed cost-benefit analysis model was implemented as a software tool for convenient use. Our research results can be used not only for those who want to evaluate the RFID technology prior to actual deployment but also by the researchers in this area.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.81-89
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• 2007

The purpose of this study is to develop data base and interface for sofa consumers and sofa designers. The human sensibility ergonomics method was used to find the consumer needs and Quality Function Deployment (QFD) method was used to extract the designing characteristics required for sofa production. About 200 words and 100 images were gathered from sofa and furniture related catalogs and internet sites to find the best emotional words and images that can express the various sofa aspect. Among the collected words and images, 34 emotional words were selected for sensibility experiment according to the opinions of experts, relations of closeness and frequency of use, and 50 images were selected for the experiment by the diversity. Selected words and images were used for the semantic differential method with 94 subjects, and sensibility characteristics of sofas were defined through various statistical analysis methods including basic statistical analysis, factor analysis and multi-dimensional scale. In reflecting design characteristics of sofas, design factors of sofas were divided into backrest, seat, armrest, neck support and leg, and relative importance of each factor for design was determined with analytic hierarchy process (AHP) by utilizing the experts' opinions. Based on the results above, relationship analysis between emotional evaluation results and design factors was performed. Also, as various sofa images are presented diagrammatically through multidimensional scaling method, it can be used as an important tool for the development of sofa design. This study will contribute improving the product quality of sofas as it enables applying consumer needs into the sofa design.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.5
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• pp.714-723
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• 2000

The purpose of this study is to develop functional and sensible brassiere for middle-aged women. As a methodology, engineering design process, especially, QFD(Quality Function Deployment) was adopted to translate consumer's needs into product design parameters. Wearing tests of commercial brassiere were performed for the development o subjective measurement scale. The environmental condition was controlled at 28$\pm$1$^{\circ}C$, 65$\pm$3%RH. As results, subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. Regression equations with the subjective evaluation descriptors were developed for the prediction of wearing comfort of brassiere. (R2=.82) The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap.