• 대한공업교육학회지
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• v.42 no.1
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• pp.87-105
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• 2017

The purpose of this study was to verify that students' interest in team activities for problem solving, the effect of interest on it, and students' changes in perceptions and their behavioral characteristics in the process of problem solving. The study reviewed documents prepared by students, such as work sheets, descriptive questionnaires, works and their photos, student activity photos and observation journals of teachers. The results of this research are as below. First, a problem solving team activity for making a model car was considered an interesting assignment by more than 90% of male/female students. The fact that female students could be more focused on this assignment than male students was discovered. Interest in the assignment not only had an influence on the points from the start (the blueprint) to the end (model cars completed based upon the designs) of problem solving, but also provided the traction power behind the assignment. Second, the problem solving team activity allowed the students to change their existing recognition (thoughts) while positively taking a lead or indirectly utilizing various learning experiences (including experiences of failure). Third, $2^{nd}$ graders in middle school had a tendency to solve problems in dependently rather than to receive help from others when they encountered problematic situations.

• Journal of Korea Technology Innovation Society
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• v.20 no.2
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• pp.368-386
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• 2017

The purpose of this study is to present the technology value model based on profit approach and IITP practical guide for Ethernet network technology, which is the core technology of autonomous vehicles and connected cars in the hyper-connected industry. In-vehicle network, Ethernet technology, Ethernet port count, port pricing, and application data for technology assessment are sources of global market research organizations. The data on the company's COGS (Cost of Goods Sold), operating capital requirement, capital expenditure, and income statement data are used by the Bank of Korea's Business Analysis Report. According to the results of the study, the product market size was estimated to be US $470.3 billion and the technology market size was $52.1 billion over the seven years of economic life cycle of technology. The market value of the technology was estimated to be $260 million reflecting the possibility of entry into the market. In the case of the corporate management analysis report, the average value of the IITP and the top 25% were $0.7 million and $40.2 million, respectively. -27.8 million, and -73.6 million dollars respectively. This implies that government support for policy support is needed when conducting corporate R&D with high cost-to-sales ratio. The results of this study can be used as a reference for the evaluation of technology demand based ICT R&D technology in the industrial internet market in the fourth industrial revolution era.

• The Journal of the Acoustical Society of Korea
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• v.22 no.5
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• pp.375-382
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• 2003

Lip-reading technique based on bimodal is to enhance speech recognition rate in noisy environment. It is most important to detect the correct lip-image. But it is hard to estimate stable performance in dynamic environment, because of many factors to deteriorate Lip-reading's performance. There are illumination change, speaker's pronunciation habit, versatility of lips shape and rotation or size change of lips etc. In this paper, we propose the IIR filtering in time-domain for the stable performance. It is very proper to remove the noise of speech, to enhance performance of recognition by digital filtering in time domain. While the lip-reading technique in whole lip image makes data massive, the Principal Component Analysis of pre-process allows to reduce the data quantify by detection of feature without loss of image information. For the observation performance of speech recognition using only image information, we made an experiment on recognition after choosing 22 words in available car service. We used Hidden Markov Model by speech recognition algorithm to compare this words' recognition performance. As a result, while the recognition rate of lip-reading using PCA is 64%, Time-domain filter applied to lip-reading enhances recognition rate of 72.4%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.609-615
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• 2014

Due to the recent global recession, the car industry demand levels have plummeted which led to a crisis in the automotive parts industry for the first time in history. Since the fourth quarter of 2008, the automotive parts manufacturers in America have faced a record loss and those in Japan and Europe who also had a strong track record are facing a weak economy. In addition, the domestic automotive parts industry is also affected by the global economic crisis. This research is that the relative efficiency analysis utilizing the DEA has done on the object of 25 small and medium-sized automotive parts manufacturers publicly listed, As the efficiency analysis result 6 of 25 manufacturers are efficient in CCR model and 12 manufactures have shown efficiency in BCC model, the efficiency analysis in consideration of the manufacturer size. The manufacturers with efficiency 1 in 25 manufacturers are DMU 1, 5, 7, 10, 18, 24 and the relatively benchmarking objects in other manufactures are DMU 1, 10, 24, Based on the results of this research, a direction to the domestic automotive parts manufacturers as well as a significant information will be provided in managing the companies in the future by the improvement of management efficiency through the practical efficiency analysis.

• Review of Culture and Economy
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• v.17 no.2
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• pp.81-102
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• 2014

As carbon dioxide, the main greenhouse gas, is generally emitted by vehicles, the development and distribution of electric cars is important for the sustainability of environmentally-friendly tourism, especially in national parks. National parks in Korea, however, still see the use of traditional vehicles powered by internal combustion engines in the handling of visitors and the transportation of goods and staff. Such engines being the cause of environmental problems such as exhaust emission and noise pollution, the introduction of electric cars in national parks is needed. This study aims to analyze the economic value of electric cars in national parks as well as contribute to the development of the Green Transportation model in tourism destinations. The study used a logit model to estimate the willingness to pay for the introduction of electric cars in national parks. Adults over the age of twenty, with gender and age apportioned equally, were surveyed using questionnaires that included dichotomous as well as demographic questions. The findings show that the amount an individual is willing to pay for the purpose of environmental conservation is 3,948 won, while the value the national parks would derive from the use of electric cars is 56,138,130,000 won. The introduction of electric cars in national parks is expected to offer both direct and indirect benefits while helping to improving the environment of the national parks by eliminating exhaust emission and noise. This introduction would also be a response to climate change that can be taken by society as a whole.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.111-117
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• 2021

This research work is to suggest the experimental results capable of solving an initial unsuitability of combustion and environment in a constant volume combustion chamber by using LFG(Land Fill Gas) which consists of 40% CO₂ and 60% CH₄. The experimental condition is set as 0.9~1.6 of air-fuel ratio, 3bar of combustion pressure, 25℃ of room temperature, methane for using gas, and 2.5~4.5 of Pre-chamber hole sizes. As a result, it can be seen that diffusion of initial flame is significantly increased by M3.0 model comparing with other one. The reason for the characteristics is that orifice effect is extremely improved by 0.9, 1.0, and 1.2 of air-fuel ratio comparing with other one. Consequently, this experiment is shown that M3.0 model is partially capable of improving combustion performance than a conventional ignition plug in case of applying to LFG with Pre-chamber design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.671-678
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• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.17-25
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• 2010

In Korea, the importance of walking has not been stood out in relief because of the rapid increase of a car on a drastic economic growth in the past half a century. Walking has failed to be recognized as a traffic measure or one of basic human rights. Therefore this study brings up problems of weakened walking right from increase of cars and examines reinforcing policies for walking right of advanced countries. And this study presents institutional devices for introducing walking safety measures of advanced countries reflecting pedestrian satisfaction and opinions about walking right. The results of this study are, First, pedestrians' walking liberty is guaranteed, Second, how to repair walking environment is searched and practical measures are analyzed to find out what is applicable to Korea, can reduce pedestrian accidents and is wanted by pedestrians using GAP analysis and Structural Equation. Third, basic data for upcoming selection of policies are presented by analyzing pedestrian satisfaction assuming that selected measures are operated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.371-378
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• 1987

Free and total amino acids of before and after the heating of the small shrimps were analysed quantitatively, in order to confirm the role of amino acids as important precursors of cooked odor components. Differences of free amino acids contents of the three samples were slightly reconized but free amino acids contents of all sample decreased as about half by heating, It seems that decreased amino acids participate In volatile components of the Small Shrimps. (Sergia lucens Hancen, Euphausia Surperba and Euphausia pacifica Hancen). The amino-carbonyl model reaction was carried out, in order to confirm formation mechanism of volatile compounds of the small shrimps during cooking. The model systems constituted by diluted solutions. of glucose and amino acids (proline, taurine and betaine) the most containing in small shrimps. The volatile odor concentrates of model system were obtained by simultaneous distillation and extraction with Nickerson's apparatus. The odor concentrates of model systems(I, III) had not small shrimp-like odor and main compounds were 1,4,5,6-tetrahydro-2-acetopyridine and 2-acetyl pyridine. In model system II, hetero ring nitrogen and sulfur compounds identified in small shrimps were not did.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.99-120
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• 2010

Due to the wide spread of customers' frequent access of non face-to-face services, there have been many attempts to improve customer satisfaction using huge amounts of data accumulated throughnon face-to-face channels. Usually, a call center is regarded to be one of the most representative non-faced channels. Therefore, it is important that a call center has enough agents to offer high level customer satisfaction. However, managing too many agents would increase the operational costs of a call center by increasing labor costs. Therefore, predicting and calculating the appropriate size of human resources of a call center is one of the most critical success factors of call center management. For this reason, most call centers are currently establishing a department of WFM(Work Force Management) to estimate the appropriate number of agents and to direct much effort to predict the volume of inbound calls. In real world applications, inbound call prediction is usually performed based on the intuition and experience of a domain expert. In other words, a domain expert usually predicts the volume of calls by calculating the average call of some periods and adjusting the average according tohis/her subjective estimation. However, this kind of approach has radical limitations in that the result of prediction might be strongly affected by the expert's personal experience and competence. It is often the case that a domain expert may predict inbound calls quite differently from anotherif the two experts have mutually different opinions on selecting influential variables and priorities among the variables. Moreover, it is almost impossible to logically clarify the process of expert's subjective prediction. Currently, to overcome the limitations of subjective call prediction, most call centers are adopting a WFMS(Workforce Management System) package in which expert's best practices are systemized. With WFMS, a user can predict the volume of calls by calculating the average call of each day of the week, excluding some eventful days. However, WFMS costs too much capital during the early stage of system establishment. Moreover, it is hard to reflect new information ontothe system when some factors affecting the amount of calls have been changed. In this paper, we attempt to devise a new model for predicting inbound calls that is not only based on theoretical background but also easily applicable to real world applications. Our model was mainly developed by the interactive decision tree technique, one of the most popular techniques in data mining. Therefore, we expect that our model can predict inbound calls automatically based on historical data, and it can utilize expert's domain knowledge during the process of tree construction. To analyze the accuracy of our model, we performed intensive experiments on a real case of one of the largest car insurance companies in Korea. In the case study, the prediction accuracy of the devised two models and traditional WFMS are analyzed with respect to the various error rates allowable. The experiments reveal that our data mining-based two models outperform WFMS in terms of predicting the amount of accident calls and fault calls in most experimental situations examined.