• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.446-455
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• 2017

The improvement of resistance performance for the 4.99 ton class fishing boats was shown. The 4.99 ton fishing boats are the most commonly used one in the Korean coastal region. The evaluation of resistance performance was estimated by the Computational Fluid Dynamics (CFD) analysis. The CFD simulation was performed by the validation for various types of bow shapes on the hull. The optimized hull form from the simulation was selected and showed the best resistance performance. This hull type was tested on the towing tank in the National Institute of Fisheries Science (NIFS). The effective horsepower (EHP) was estimated by the resistance test on the towing tank with the bare hull condition. The drag force on the three service speed conditions was obtained for the resistance analysis to power prediction. The measured drag forces are compared with the results from the CFD simulation with one another. As results of the model tests, it was confirmed that the shape of the bow is an important factor in the resistance performance. The effective horsepower decreased about 30% in comparison with the conventional hull form. Also, the resistance performance improved the reduction of required horsepower, which especially contributed to the energy-saving for the fisheries industry. In the CFD analysis, the resistance performance improved slightly. In this case, the ratio of the residual resistance ($C_R$) in the total resistance ($C_T$) was high. Therefore, the CFD analysis was not enough to satisfy with reflection for the free surface and wave form in the CFD procedure. Both model test and CFD calculation in this study can be applied to the initial design process for the coastal fishing vessel.

• Journal of Environmental Impact Assessment
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• v.19 no.4
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• pp.381-396
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• 2010

It is essential to consider strategies, spatial planning, and reflection of sustainability for the creation of sound urban spaces. To this end, there is a need for plans that can secure better sustainability through strategic environmental assessment (SEA) of plans. This study examined the literature and available precedent to develop a SEA model for administrative plans for urban development including metropolitan plans, urban master plans and urban management plans. In the course of development of the model, environmental issues associated with the urban plans were analyzed by classifying them into ten categories, including "spatial planning," "conservation planning," "greenbelt systems," "habitats." and etc. according to their rank. Furthermore, those issues were reflected on the development of environmental evaluation indices for the plans. Overall and detailed environmental indices that can be applied to the administrative plans for urban development including metropolitan plans, urban master plans and urban management plans were devised for five stages: (1) Establishment of development goals and strategy, (2) Analysis of current status and characteristics, (3) Conceptualization of spatial structure, (4) Planning for each department, and (5) Execution and management. Sub plans are more detailed and concrete. Criteria based on the evaluation indices, when performing evaluations on plans based on each environmental assessment index in reference to experts and the literature, were used to forecast their effects, i.e. whether they had a positive, negative, or no effect or relationship, or whether their effects was uncertain. Based on the forecasts, this study then presents means to establish more improvable plans. Furthermore, by synthesis of the effects according to each index and integration of the process, plans were analyzed overall. This study reflects the characteristics of the present time period based on issues in the SEA process and techniques in upper level administrative plans being newly established, and presents them according to the stage of each plan. Furthermore, by forecasting the effect of plans by stage, this study presents proposals for improvement, and in this aspect, can be meaningful in promoting plan improvements through SEA.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.83-92
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• 2005

An electromagnetic acoustic transducer (EMAT) is a unique probe that does not require a couplant or gel and also can usually generate or detect an ultrasonic wave into specimens across a small gap. It, therefore can be applied in a noncontact mode with a high degree of reproducibility. Especially stiffness of composites depends on layup sequence of CFRP(carbon fiber reinforced plastics) laminates. It is very important to evaluate the layup errors in prepreg laminates. A nondestructive technique can therefore serve as a useful measurement for detecting layup errors. This shear wave for detecting the presence of the errors is very sensitive. A decomposition model has been used in the interpretation and prediction of test results. Test results have been com pared with model data. It is found that the high probability shows between tests and the model utilized in characterizing cured layups of the laminates. Also a C-scan method was used for detecting layup of the laminates because of extracting fiber orientation information from the ultrasonic reflection caused by structural imperfections in the laminates. Therefore, it was found that interface C-scan images show the fiber orientation information by using two-dimensional fast Fourier transform (2-D FFT).

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.12-20
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• 2002

An integrated analysis of kerosine/LOX based KSR-III rocket body/plume flowfield has been performed. The analysis has been executed employing three kind of gas thermo-chemical models including calorically perfect gas, multiple species chemically reacting gas, and chemically frozen gas models and their effect on rocket flowfield has been accessed to provide the most appropriate gas thermo-chemical model which meets a specific purpose of performing rocket body and plume analysis. The finite-rate chemically reacting flow solution exhibited higher temperature throughout the flowfield than other gas models due to the increased combustion gas temperature caused by the chemical reactions within the nozzle. All the reactions were dominated only in the shear layer and behind the barrel shock reflection region where the gas temperature is high and the effect of finite-rate chemical reactions on the flowfield was found to be minor. However, the present plume computation including finite-rate chemical reactions revealed major reactions occurring in the plume and their reaction mechanisms and as well.

• Human Ecology Research
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• v.56 no.1
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• pp.71-84
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• 2018

This study presents a case of a visual merchandising course adopting a problem-based learning (PBL) model, as a part of shop manager training program for high school students. Various vocational training classes are actively developed for vocational high schools, yet programs in the home economics area are relatively lacking. In particular, education programs for shop manager training are urgently required due to the high demand of this job in the fashion industry. The PBL model, which reflects constructionist learning theory, is considered for this visual merchandising course in order to help develop the ability of students to creatively apply their knowledge on real-world problems through self-driven learning. For the purpose of job analysis, two problem areas were identified through interviews conducted with shop managers who work for apparel shops in department stores. Based on the results of the interviews, professors and high school teachers developed two PBL instructional modules. The developed module courses were implemented with 2 classes of vocational high school students. The learning outcome was examined through the analysis of a student survey and reflection journals. It was apparent that the PBL courses effectively attracted the interests of learners in vocational training and improved their understanding of the contents as well as cooperation skills. The results of this study indicate that implementing the PBL model for the training of store managers can contribute to the vocational training programs for high school students.

• Journal of KIISE
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• v.43 no.7
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• pp.801-811
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• 2016

Self-adaptive systems (SASs) can change their goals and behaviors to achieve its ultimate goal in a dynamic execution environment. Existing approaches have designed, at the design time, utility functions to evaluate and predict the goal satisfaction, and set policies that are crucial to achieve each goal. The systems can be adapted to various runtime environments by utilizing the pre-defined utility functions and policies. These approaches, however, may or may not guarantee the proper adaptability, because system designers cannot assume and predict all system environment perfectly at the design time. To cope with this problem, this paper proposes a new method of dynamic decision making, which takes the following steps: firstly we design a Dynamic Decision Network (DDN) with environmental data and goal model that reflect system contexts; secondly, the goal satisfaction is evaluated and predicted with the designed DDN and real-time environmental information. We furthermore propose a dynamic reflection method that changes the model by using newly generated data in real-time. The proposed method was actually applied to ROBOCODE, and verified its effectiveness by comparing to conventional static decision making.

• Korean Journal of Comparative Education
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• v.24 no.3
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• pp.245-265
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• 2014

The purpose of this research is to find the features of HLC institutional accreditation model and the implication on the second period institutional accreditation of Korea. This research focus on accreditation model, accreditation period, comprehensive evaluation, criteria, decision making for accreditation status and accreditation supporting system. This research draws following suggestions to the second period institutional accreditation of Korea. 1. The institutional accreditation should apply various accreditation models according to the features of institute. 2. The institutional accreditation should focus on the autonomous quality improvement of institute with the quality assurance. 3. The quantitative evaluation should be reduced and qualitative evaluation based on mission and objects should be reinforced. 4. The interim evaluation should be strictly enforced for quality improvement. 5. The government should enlarge reflection the results of accreditation on financial aid to universities. 6. The web-based accreditation supporting system interworking with "Higher Education in Korea" service is needed.

• Educational Technology International
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• v.11 no.1
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• pp.93-117
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• 2010

The purpose of this study was to develop the problem solving instruction facilitating novice learner to represent the problem. For the purpose, we mainly focused on three aspects of problem solving. First, learner should represent the targeted problem and its solutions for problem solving. Second, from crucial notions of cognitive load theory, learner's mental load should be optimized for problem representation. Third, for optimizing students' mental load, experts may support making their thinking more visible and mapping from their intuition to expert practice. We drew the design principles as follows. First, since providing worked examples for the targeted problem has been considered to minimize analogical errors as well as reduce cognitive load in problem representation at line of problem solving and instructional research, it is needed to elaborate the way of designing. The worked example alternatively corresponds to expert schema that consists of domain knowledge as well as strategies for expert-like problem representation and solution. Thus, it may help learner to represent what the problem is and how to solve it in problem space. Second, principle can be that expert should scaffold learner's self-explanations. Because the students are unable to elicit the rationale from worked example, the expert's triggering scaffold may be critical in that process. The unexplained and incomplete parts of the example should be completed not by expert's scaffold but by themselves. Critical portion of the expert's scaffold is to explain about how to apply and represent the given problem, since students' initial representations may be reached at superficial or passive pattern of example elaboration. Finally, learner's mental model on the designated problem domain should be externalized or visualized for one's reflection as well as expert's scaffolding activities. The visualization helps learner to identify one's partial or incorrect model. The correct model of learner could be constructed by expert's help.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.809-816
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• 2006

More than effectively judging the existence of reinforcing bars under multi boundary layers and void shapes in concrete, this study aims to develop the analysis algorithm of radar response on multi boundary layers in reinforced concrete and radar capable of estimation of the shape of specific voids in plain concrete. To detect or estimate reinforcing bars and void shapes in these conditions, the simulation analysis model of transmission and reflection wave of electromagnetic radar is used. This radar simulation model is carried out with reinforced or non reinforced concrete of various boundary conditions and void shapes. And, the output signals (images) of radar simulation results are calculated and represented by convolution method. As the results, it is clarified that this simulation analysis technique can be used to analyze radar response on multi boundary layers in reinforced concrete and void shapes in concrete.

• The Journal of the Acoustical Society of Korea
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• v.25 no.6
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• pp.298-304
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• 2006

This paper proposes a ray-based forward modeling scheme which is suitable for the shallow water acoustic wave propagation simulations. The proposed model comprises of ray tracings for the layered media of which sound speed profiles are interpolated linearly. considerations of plane and spherical wave reflection coefficients. and calculations of the phases and the amplitudes of eigen rays. The main characteristic of the scheme is fast simulation time due to direct calculation of the broad-band time signals in the time-domain, i.e. without transformation of the frequency-domain solutions to the time si 밍 131s. Finally, we applied the model to 4-types of test environments and compared the resulting signals with those of ORCA and Ram in order to validate the proposed model.