• Journal of the Institute of Convergence Signal Processing
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• v.23 no.3
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• pp.123-128
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• 2022

A lot of research is being done to develop a high-efficiency heat pump to save energy, and research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil is also being conducted at the same time. In order to conduct a study that does not cause frost on the outdoor unit of the heat pump regardless of the season, a constant temperature chamber like a general room that can be tested under the same conditions as in the natural state was built. The experiment was conducted by providing an environment similar to the natural state to the outdoor unit of the heat pump installed in the constant temperature chamber. As a result, the lower the outdoor temperature, the lower the efficiency of the heat pump. It wat confirmed that the lower the value, the longer it is.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.140-146
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• 2023

A lot of research is being done to develop a high-efficiency heat pump to save energy. Among them, research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil are being conducted at the same time. A constant temperature chamber that can be tested under the same conditions as natural conditions was constructed to conduct research that does not cause frost on the outdoor unit of the heat pump regardless of the season. The outdoor unit of the heat pump installed in the constant temperature chamber was simulated under the same natural conditions. As a result, it was confirmed that the mass flow rate of the refrigerant decreased as the outdoor temperature decreased, and the dryness of the refrigerant also increased linearly with the outdoor temperature.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.4_1
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• pp.797-803
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• 2024

In this study, a device was used to conduct heat to the riser by combining a cylindrical heater with the riser to maintain the molten metal above a certain temperature while continuously compensating for the shrinkage phenomenon that occurs as the molten metal solidifies in the product area. A cylindrical heater is coupled to the riser portion of the upper part of the upper mold, and a heater portion mold is formed between the riser and the cylindrical heater. The cylindrical heater is connected to a controller to control the temperature and a power supply. The cylindrical heater conducts a heat source to the molten metal located on the riser and can continuously compensate for the shrinkage of the cast product by heating the molten metal located on the riser or maintaining it at a constant temperature. The block without a riser had a large shrinkage cavity at the top, and the top became concave due to shrinkage. There is no shrinkage in the block with the Ø100 mm riser. Blocks that did not apply heaters to the Ø50 mm riser experienced shrinkage around the riser and also at the bottom. There is no shrinkage in the block with the Ø50 mm riser to which the heater was applied.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.277-285
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• 2016

The purpose of this study is to quantitatively and empirically investigate whether cartoon-realism, which is referred to as a guideline for avoiding the uncanny valley phenomenon, is actually effective. An experiment was carried out to investigate whether or not methods that try to realistically express the texture of human skin while making 3D models whose outward appearance abstract like a cartoon actually reduce the negative sentiments associated with the uncanny valley phenomenon. The results found that when human skin textures were applied to cartoon-type 3D models, the degree of eeriness significantly increased (p<0.05), while there was no change in the degree of human likeness. When cartoon-style skin textures were applied to human-type 3D models, there was no significant difference in the degree of eeriness, but the degree of human likeness significantly decreased (p<0.05). These results show that, cartoon realism is not actually effective, and rather creates a perceptual conflict and induces the uncanny valley phenomenon. The results of this study are expected to be used as quantitative and empirical data for developing design guidelines that will overcome the uncanny valley phenomenon in the future.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.153-160
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• 2015

The domestic stock market has been subjected to a major change since the September 1997 financial crisis. Foreign capital came repeat themselves in the stock market and bond market, foreign exchange market opening up domestic financial markets after the financial crisis. The domestic stock market has been most affected by domestic capital before the financial crisis. But it has been receiving an absolute influenced by foreign capital after the financial crisis. The purpose of this study is to analyze the trends in the two sections that look at any changes in the volatility of the KOSPI appears after the crisis. To this, obtained a daily weekly monthly normal distribution and kurtosis, skewness degree it should be analyze the tilt phenomenon and variability of the two intervals. This study also predict the future movement of the domestic stock market Based on this, look at the difference between the two sections. Analysis result, after the financial crisis change width has a reduction but direction of the KOSPI has appeared relatively distinct in the medium to long term. Based on this future market seems desirable the mid- to long-term investment looking for direction.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.71-76
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• 2015

Recently, light emitting diodes (LEDs) have been studied to improve their efficiencies for the uses in various fields. Particularly in the aspect of chip structure, via hole type vertical LED chip is developed for improvement of light output power, and heat dissipations. However, current vertical type LEDs have still drawback, which is current concentration around the n-contact holes. In this research, to solve this phenomenon, we introduced isolation layer under n-contact electrodes. With this sub-electrode, even though the active area was decreased by about 2.7% compared with conventional via-hole type vertical LED, we could decrease the forward voltage by 0.2 V and wall-plug efficiency was improved approximately 4.2%. This is owing to uniform current flow through the area of n-contact.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.203-213
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• 2017

The purpose of this research is to suggest the direction of the domestic convenience store platform in the aging society and the fourth industrial revolution. Recently, convenience stores have been providing various lifestyle platforms by seeking new growth engines based on the reputation that the number of convenience stores has reached the saturation. In order to present the direction of development, It conducted a questionnaire survey of 78 people from domestic teenagers to 60s or older and case study of domestic and overseas convenience store platforms. Through this survey, it was found that convenience stores in Korea provide users with a convenient lifestyle platform, but the service for the elderly was found to be in shortage compared to other countries. Convenience stores should offer lifestyle platform services for the elderly, as they provide lifestyle platform services for people in 20s and 30s. This will make the convenience store a competitive lifestyle platform service in the 4th industrial revolution. In addition, it is necessary to continuously study the CVS living platform service according to the changing social phenomenon in the future.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.67-74
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• 2020

In this paper, we propose to present a storytelling education plan for the development of realistic content. The need is emerging in the content industry for realistic content along with technological convergence as development of media technology. This phenomenon is being accelerated by COVID-19. In 2019, the government set up strategies to secure future growth engines, announced "three major innovation strategies" in the content industry, and emphasized "fostering leading realistic content." Realistic content is a content that users can experience directly. It is first-person storytelling that should be dealt with as important as the development of technology in the production of realistic content. In this paper, the results of storytelling classes conducted at the actual educational site are analyzed, and the difference from the first-person perspective commonly used in traditional literary works is described. Through this, we present effective teaching methods that can be used to develop realistic content.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.1-6
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• 2017

Tungsten carbide (WC) has been suggested as a new buffer layer for the GaN-on-Si technology. We have investigated and optimized the sputtering condition of WC layer on the Si-substrate. We confirmed the suppression of the Si melt-back phenomenon. In addition, surface energy of WC/Si layer was measured to confirm the possibility as a buffer layer for GaN growth. We found that the surface energy(${\gamma}=82.46mJ/cm^2$) of WC layer is very similar to that of sapphire substrate(${\gamma}=82.71mJ/cm^2$). We grow GaN layer on the WC buffer by using gas-source MBE, and confirm that it is available to grow a single crystalline GaN layer.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.283-300
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• 2017

This study is to understand the work experiences of nursing students under preceptorship in 3+1 year program, and suggests effective practice to prevent stopping nursing profession. Four focus group interviews were made with 23 nursing students in 3+1 year program. Data were analyzed through the grounded theory of Corbin and Strauss' (2008). Through comparative analysis, central phenomenon of was 'looking for lighthouse'. The causal condition was 'opportunity to learning practice'. Contextual conditions were 'mood of being a true nurse', 'getting vivid information about clinical field', and 'lack of students perception about preceptorship'. Intervention conditions were 'work environment', 'proactive learning' and 'attachment to the hospital'. Action/interaction strategies were 'adjustment to diverse demands of patients and guardians', 'feeling as if it were one's own affair', and 'looking as much as knowing'. Consequence were 'pride' and 'itinerary of learning as a new graduate nurse'. This study is meaningful because it gives useful basis to nursing students in the process of 'looking for lighthouse'.