• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.67-75
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• 2016

This paper investigates how artificial individuals with behavioral memory circuits adaptively evolve with respect to given environments on a cell-level simulation framework simulating artificial individuals. This makes it possible for us to analyse the advantages of artificial individuals with behavioral memory circuits against the simple artificial individuals that can do only simple reactions with respect to the environments and to know which advanced reactions are possible. In order to do this analysis, we experimented various tests on a specific prey pattern and examined the results. As a first experiment, we tested that artificial individuals with four memory steps competed against from those without memory step to those with three memory steps. Experimental results showed that the artificial individuals with four memory steps were superior to most others. However, artificial individuals with two memory steps were better than those with four memory steps. This was caused that the artificial individuals with two memory steps could evolve faster than those of four memory steps. In a second experiment that all types of artificial individuals are simultaneously evolved, the artificial individuals with two memory steps also showed the best result in the experiment. We could conclude that the artificial individuals with memory was better than those without memory and the best memory steps of artificial individuals were depended on the complexity of prey patterns.

• Korean Journal of Remote Sensing
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• v.15 no.1
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• pp.9-20
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• 1999

The use of climatic information is essential in the industial society. More specialized weather servies are required to perform better industrial acivities including agriculture. Especially, crop models require daily weather data of crop growing area or cropping zones, where routine weather observations are rare. Estimates of the spatial distribution of daily climates might complement the low density of standard weather observation stations. This study was conducted to estimate the spatial distribution of daily minimum and maximum temperatures in Korean Peninsula. A topoclimatological technique was first applied to produce reasonable estimates of monthly climatic normals based on 1km $\times$ 1km grid cell over study area. Harmonic analysis method was then adopted to convert the monthly climatic normals into daily climatic normals. The daily temperatures for each grid cell were derived from a spatial interpolation procedure based on inverse-distance weighting of the observed deviation from the climatic normals at the nearest 4 standard weather stations. Data collected from more than 300 automatic weather systems were then used to validate the final estimates on several dates in 1997. Final step to confirm accuracy of the estimated temperature fields was comparing the distribution pattern with the brightness temperature fields derived from NOAA/AVHRR. Results show that differences between the estimated and the observed temperatures at 20 randomly selected automatic weather systems(AWS) range from -3.$0^{\circ}C$ to + 2.5$^{\circ}C$ in daily maximum, and from -1.8$^{\circ}C$ to + 2.2$^{\circ}C$ in daily minimum temperature. The estimation errors, RMSE, calculated from the data collected at about 300 AWS range from $1.5^{\circ}C$ to 2.5$^{\circ}C$ for daily maximum/minimum temperatures.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.489-495
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• 2018

In this paper, we designed and fabricated WLAN / UWB communication antennas operating at 3.3 [GHz] and 5 [GHz] bands in order to effectively use the high-speed communication network system that improved antenna miniaturization, gain and radiation pattern. Microstrip patch antennas were chosen to improve the bandwidth. The slot width, length, and transmission line width were calculated using the theoretical formula for each step. Simulation results show that the return loss is -14.053 [dB] at 3.3 [GHz] and -13.118 [dB] at 5 [GHz]. The gain showed a value of 2.479 [dBi] at 3.3 [GHz] and a value of 3.317 [dBi] at 5 [GHz]. After optimizing it with the CST Microwave Studio 2014 program, which can be 3D-designed, Based on these results, we investigated the performance of antennas by measuring their characteristics. In recent years, WLAN, which is a variety of wireless technologies that are continuously developing, and UWB, which is a communication technology which is increasing in frequency band due to an increase in demand of the technology users, is used for a high speed wireless communication system. Communication seems to be possible.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.6
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• pp.177-189
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• 2018

Business environment is always full of challenges. Despite various strategic efforts, there are so many failure cases of misfit. With the weaker resource base and institutional foundation, startup firms find it more difficult to find the right spot in the stiff competition. In the middle of evolutionary process, the startup firms need proper strategies meeting the differential challenges along the multiple stages of growth. Following the idea of product life cycle, this study applies the four stages of growth-startup, initial growth, accelerated growth, matured, and decliing. The next step for the startup manager is meeting each stage of growth with proper strategic efforts, including strategy, structure, decision-making pattern, and control method. When the knowledge factor is introduced, there is a potential for higher performance. Based on the 'Detailed Survey on Startup Ventures in 2017,' this study explores the impact of the government subsidy program on the firm competitiveness and performance-along the four stages of growth. In each stage, the strategy factors showed differential impact.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.79-87
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• 2021

The digital workflow of optical impressions by the intraoral scanner and CADCAM manufacture of dental prostheses is actively developing. The complex process of traditional impression taking, definite cast fabrication, wax pattern making, and casting has been shortened, and the number of patient's visits can also be reduced. Advances in intraoral scanner technology have increased the precision and accuracy of optical impression, and its indication is progressively widened toward the long span fixed dental prosthesis. This case report describes the long span implant case, and the operator fully utilized digital workflow such as computer-guided implant surgical template and CAD-CAM produced restoration after the digital impression. The provisional restoration and customized abutments were prepared with the optical impression taken on the same day of implant surgery. Moreover, the final prosthesis was fabricated with the digital scan while utilizing the same customized abutment from the provisional restoration. During the data acquisition step, stl data of customized abutments, previously scanned at the time of provisional restoration delivery, were imported and automatically aligned with digital impression data using an 'A.I. abutment matching algorithm' the intraoral scanner software. By using this algorithm, it was possible to obtain the subgingival margin without the gingival retraction or abutment removal. Using the digital intraoral scanner's advanced functions, the operator could shorten the total treatment time. So that both the patient and the clinician could experience convenient and effective treatment, and it was possible to manufacture a prosthesis with predictability.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.191-209
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• 2022

This paper is a review of studies that focus on the prediction of a won/dollar exchange rate before and after the covid 19 pandemic. The Korea economy has an unprecedent situation starting from 2021 up till 2022 where the won/dollar exchange rate has exceeded 1,400 KRW, a first time since the global financial crisis in 2008. The US Federal Reserve has raised the interest rate up to 2.5% (2022.7) called a 'Big Step' and the Korea central bank has also raised the interested rate up to 2.5% (2022.8) accordingly. In the unpredictable economic situation, the prediction of the won/dollar exchange rate has become more important than ever. The authors separated the period from 2015.Jan to 2022.Aug into three periods and built a best fitted ARIMA/ARDL prediction model using the period 1. Finally using the best the fitted prediction model, we predicted the won/dollar exchange rate for each period. The conclusions of the study were that during Period 3, when the usual relationship between exchange rates and economic factors appears, the ARDL model reflecting the variable relationship is a better predictive model, and in Period 2 of the transitional period, which deviates from the typical pattern of exchange rate and economic factors, the SARIMA model, which reflects only historical exchange rate trends, was validated as a model with a better predictive performance.

• Clean Technology
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• v.28 no.3
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• pp.227-231
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• 2022

The demand for high-voltage power devices is rising in various industries, but especially in the transportation industry due to autonomous driving and electric vehicles. IGBT module parts of 3.3 kV or more are used in the power propulsion control device of electric vehicles, and the procurement of these parts for new construction and maintenance is increasing every year. In addition, research to optimize high-voltage IGBT parts is urgently required to overcome their very high technology entry barrier. For the development of high-voltage IGBT devices over 3.3 kV, the resistivity range setting of the wafer and the optimal conditions for major unit processes are important variables. Among the manufacturing processes to secure the optimal junction depth, the optimization of the diffusion process, which is one step of the unit process, was examined. In the diffusion process, the type of gas injected, the injection time, and the injection temperature are the main variables. In this study, the range of wafer resistance (Ω cm) was set for the development of high voltage IGBT devices through unit process simulation. Additionally, the well drive in (WDR) condition optimization of the diffusion process according to temperature was studied. The junction depth was 7.4 to7.5 ㎛ for a ring pattern width of 23.5 to25.87 ㎛, which can be optimized for supporting 3.3 kV high voltage power devices.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.143-151
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• 2010

Fingerprint classification is a step to increase the efficiency of an 1:N fingerprint recognition system and plays a role to reduce the matching time of fingerprint and to increase accuracy of recognition. It is difficult to classify fingerprints, because the ridge pattern of each fingerprint class has an overlapping characteristic with more than one class, fingerprint images may include a lot of noise and an input condition is an exceptional case. In this paper, we propose a novel approach to design a stochastic model and to accomplish fingerprint classification using a directional characteristic of fingerprints for an effective classification of various qualities. We compute the directional value by searching a fingerprint ridge pixel by pixel and extract a directional characteristic by merging a computed directional value by fixed pixels unit. The modified Markov model of each fingerprint class is generated using Markov model which is a stochastic information extraction and a recognition method by extracted directional characteristic. The weight list of classification model of each class is decided by analyzing the state transition matrixes of the generated Markov model of each class and the optimized value which improves the performance of fingerprint classification using GA (Genetic Algorithm) is estimated. The performance of the optimized classification model by GA is superior to the model before the optimization by the experiment result of applying the fingerprint database of various qualities to the optimized model by GA. And the proposed method effectively achieved fingerprint classification to exceptional input conditions because this approach is independent of the existence and nonexistence of singular points by the result of analyzing the fingerprint database which is used to the experiments.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.313-321
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• 2022

As 5G is getting developed, people are getting interested in immersive content. Some predicts that immersive content may be implemented in real life such as holograms, which were only possible in movies. Holograms, which has been studied for a long time since Dennis Gabor published the basic theory in 1948, are constantly developing in a new direction with digital technology. It is developing from a traditional optical hologram, which is produced by recording the interference pattern of light to a computer generated hologram (CGH) and a digital hologram printer. In order to produce a hologram using a digital hologram printer, holographic element (Hogel) image must first be created using multi-view images. There are a method of directly photographing an actual image and a method of modeling an object using 3D graphic production tool and rendering the motion of a virtual camera to acquire a series of multi-view images. In this paper, we propose a new method of getting image, which is one of the visual effect, VFX, producing multi-view images using chroma key composition. We shoot on the green screen of actual object, suggest the overall workflow of composition with 3D computer graphic(CG) and explain the role of each step. We expected that it will be helpful in researching a new method of image acquisition in the future if all or part of the proposed workflow to be applied.

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.21-36
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• 2021

This study investigated the means-end chain theory more concretely through the APT hard laddering technique. This is carrying out a questionnaire survey targeting users by hair salon type, and the items drawn from the qualitative laddering technique are applied. The technique is a comparative analysis of each attribute, consequences, and value item by analyzing each step's questions. The results are as follows. First, hairdresser's ability, acceptance of individual-customized opinions, and cheap price were the most mentioned items in the selection attributes. As for the consequences items, image transformation, neatness, novelty, and psychological stability were drawn in order. The items indicated as important among the value items were satisfaction, followed by happiness, confidence, beauty, and bond. Second, the remarkable selection attributes, irrelevant of hair salon type, was revealed as hairdresser's ability and the key values pursued when using a hair salon were drawn as satisfaction, confidence, and beauty. From this result, it was found that meeting the desire of consumers using hair salons can be linked with ultimately pursued values. It was also verified that partial differences were shown by hair salon type and this meant that consumers' desire and expected benefits were different by hair salon type. Although this study drew value perception through comparison with hair salon types based on the means-end chain theory, it was confirmed that the most important selection attribute was hairdresser's ability and they select and use hair salons to gain satisfaction and confidence.