• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.1-12
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• 2021

Technologies for an MVDC(medium voltage direct current) distribution system are being considered as an effective alternative to overcome the interconnection delay issues of PV systems. However, the implementation of a DC distribution system might lead to economic problems because of the development of DC devices. Therefore, this paper deals with the scale of a PV plant based on its capacity and proposes hosting-capacity models for PV systems to establish a network to evaluate the feasibility of an MVDC distribution system. The proposed models can be classified as AC and DC distribution systems by the power-supply method. PV systems with hundreds of MW, dozens of MW, and a few MW can be categorized as large-scale, medium-scale, and small-scale models, respectively. This paper also performed modeling for an economic evaluation of MVDC distribution system by considering both the cost of AC and DC network construction, converter replacement, operation, etc. The profit was composed of the SMP and REC rate of a PV plant. A simulation for economic evaluation was done for the MVDC distribution system using the present worth and equal-principal costs repayment method. The results confirmed that the proposed model is a useful tool to evaluate economic issues of a DC distribution system.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1528-1534
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• 2020

This study examines the trends of the domestic age-friendly industry, examines the ingredients notified by the Ministry of Food and Drug Safety of aging cosmetics, and analyzes the research trends of raw materials other than the notices, and prepares data for the aged-friendly industry to quickly cope with changes in the cosmetics industry environment and aging people. I wanted to. In addition to the ingredients notified by the Ministry of Food and Drug Safety, research trends on the development of ingredients for anti-aging cosmetics are examined, and the anti-aging effects of each ingredient are examined. Through this, 'aging' and 'cosmetics', 'Anti-Aging', 'Anti-Aging', etc. In order to lead the development of anti-aging cosmetics related to the aging industry, research activities on products that are effective in preventing aging by strengthening the skin in addition to the four ingredients notified by the Ministry of Food and Drug Safety are constantly being conducted. In the functional cosmetics field notified by the Minister of Food and Drug Safety, it is believed that various basic research activities should be conducted so that research on anti-aging can be scientifically supported rather than a single research.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.422-428
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• 2021

This study surveyed residents and public officials for the projects to make smart-city plans of Geumsan-gun. First, domestic and foreign cases related to smart city projects were reviewed. The local status of Geumsan-gun was investigated regarding various aspects of the natural, social, urban environment, and smart-city facilities. The survey results were as follows. Overall, more than half of the survey respondents said they were satisfied with their housing quality. Several problems in their areas, such as inefficient welfare system, shortage of parking space, and industrial infrastructure, were reported. On the other hand, tourism and leisure facilities, health care support systems, industries to boost the economy, and the job market were also important issues. The problem was that the regional problems mentioned above were not in line with their preferences for smart-city services. The implications of the survey results could be summed up as follows. The groupware surveys of Geumsan-gun should be used as survey tools, whereas IT survey tools (Google, Survey Monkey, etc.) should be used for locals. In particular, a survey targeting residents should ask plain and compact questions taking advantage of local gatherings. It is also important to have a pilot-survey with relevant public officials and select related projects and regional issues. The survey of local residents and public officials is a prerequisite for promoting smart city projects. The smart city project shall reflect the needs of residents while solving community problems by considering the survey results and local conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.352-361
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• 2021

An underwater positioning method that can be applied to structures for underwater construction is being developed at the Korea Institute of Ocean Science and Technology. The method uses an extended Kalman filter (EKF) based on an inertial navigation system for precise and continuous position estimation. The observation matrix was configured to be variable in order to apply asynchronous measured sensor data in the correction step of the EKF. A Doppler velocity logger (DVL) can acquire signals only when attached to the bottom of an underwater structure, and it is difficult to install and recover. Therefore, a complex sensor device for underwater structure attachment was developed without a DVL in consideration of an underwater construction environment, installation location, system operation convenience, etc.. Its performance was verified through a water tank test. The results are the measured underwater position using an ultra-short baseline, the estimated position using only a position vector, and the estimated position using position/velocity vectors. The results were compared and evaluated using the circular error probability (CEP). As a result, the CEP of the USBL alone was 0.02 m, the CEP of the position estimation with only the position vector corrected was 3.76 m, and the CEP of the position estimation with the position and velocity vectors corrected was 0.06 m. Through this research, it was confirmed that stable underwater positioning can be carried out using asynchronous sensors without a DVL.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.86-100
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• 2020

This study is the result of a design proposal to create a history and culture complex for the "Gungjip," an Important Folklore Cultural Heritage, and its surroundings located in Namyangju, Gyeonggi Province. In particular, the purpose is to introduce a new design approach to a historical and cultural complex consisting of the Gungjip House and Hanok annexes to be opened to the public in the future; and to provide its implications for future study. Although the architectural condition of Gungjip House is well preserved, several problems have been found in the use of the site as a public space due to the lack of a plan for systematic space experience, lack of specific spatial programs, and the too much shade due to uncontrolled green areas, etc. Therefore, the plan presented in this study largely sought to respect the meaning of historical landscape as a public space and to balance with the contemporary needs. The design strategies derived through basic research are to strengthen the sense of place as a cultural heritage; to respect the ecological characteristics of the site and visual harmony with the surrounding environment; and to suggest spatial programs suitable for the contemporary needs. Based on these strategies, the framework for the entire space is conceptually composed of four spaces; Oewon, Ganjeong, Jujeong, and Huwon, and proposes systematical land use and landscape experience. The main feature of this plan is the landscape approach, which aims to preserve the architectural cultural assets in their original form, but to create a reasonable land use and meaningful landscape experience based on the sense of place.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.561-568
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• 2020

Wave measurements using X-band radar have many advantages compared to other wave gauges including wave-rider buoy, P-u-v gauge and Acoustic Doppler Current Profiler (ADCP), etc.. For example, radar system has no risk of loss/damage in bad weather conditions, low maintenance cost, and provides spatial distribution of waves from deep to shallow water. This paper presents new methods for estimating significant wave heights of X-band marine radar images using Artificial Neural Network (ANN). We compared the time series of estimated significant wave heights (Hs) using various estimation methods, such as signal-to-noise ratio (${\sqrt{SNR}}$), both and ${\sqrt{SNR}}$ the peak period (TP), and ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k). The estimated significant wave heights of the X-band images were compared with wave measurement using ADCP(AWC: Acoustic Wave and Current Profiler) at Hujeong Beach, Uljin, Korea. Estimation of Hs using ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k) yields best result.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.39-48
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• 2020

This study examined the type, the structural shapes, and the representation of Sandae, which was the stage for traditional performing arts and constructed for the purpose of imperial processions, ritual ceremonies, banquets, etc. from the Goryeo Dynasty to the Late Joseon Dynasty, and the implications of Seokgasan, which was built in the same era. First, through the history and meaning of Sandae, it was confirmed that Sandae has a homogeneity with Seokgasan, which attempted to imitate the shape of "Mountain" in the outer space. The construction of Sandae was deeply related to the tradition of famous mountains. This is consistent with the fact that 'Famous mountains and lakes" in China was symbolically replicated on the Seokgasan in the front yard of the "Cheongyeongak" in the Goryeo Dynasty. Second, Sandae and Seokgasan differed in their structural shapes, materials, and production methods, but they were used as a stage background for national events by constructing in the shape of the mountain, and appeared in various types. It can be seen that the interest in gardens and art of those days has resulted in various formative expressions of nature through the shape and symbolic meaning of the Sandae that mimics the mountain. Third, it is presumed that the square pond with lotus flowers, which is believed to have been located in the center of the garden of Shin Jaehyo's old house, and the Sugak and Seokgasan adjacent to it were not only elements of the garden, but also functioned as a background for the training and performance stage of Shin Jaehyo's students.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.406-420
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• 2021

This study used Glaser's grounded theory method for the recognition of college students' majors in counseling psychology. Among the 3rd and 4th grade students majoring in counseling psychology, 19 students participated in the study, focusing on them for 5 months and collecting data through individual interviews. As a result of analyzing the data, 103 concepts, 26 subcategories, 9 upper categories, and 1 core category were derived. As a result of the study, first, the participants wanted to relieve the burden of people's hearts and had the hope of becoming a healer. Second, among the participants, in terms of their personality and aptitude for their major field, they perceived it as joy and satisfaction, such as 'It fits well with the major,' 'I made a good choice,' and 'It became a turning point in life.' However, they also recognized the incompatibility of the major, such as disharmony of aptitude, burden of the role of counselor, and rejection of major. Third, although participants showed usefulness in their major learning, their perception of the career path in their major was acting as anxiety and conflict, but their concerns and conflicts resulted in financial difficulties, poor job conditions, and emotional exhaustion caused by long-term study. The burden of job, fear of counseling job, limit of undergraduate graduation, uncertainty of career, etc. acted as an obstacle in choosing a major career. Fourth, as a result of analyzing the interview data of the participants, a core category called' understanding and growth and the will of the counselor to realize the dream' was derived. In conclusion, the participant's perception of their major is the change and growth of themselves, the formation of a healthy relationship with others, and satisfaction with the suitability of their major and their aptitudes. It turned out to have a lasting will to do.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.96-106
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• 2020

To solve the limitation of traffic monitoring that occur from embedded sensor such as loop and piezo sensors, the thermal imaging camera was installed on the roadside. As the length of Class 1(passenger car) is getting longer, it is becoming difficult to classify from Class 3(2-axle truck) by using an embedded sensor. The collected images were labeled to generate training data. A total of 17,536 vehicle images (640x480 pixels) training data were produced. CNN (Convolutional Neural Network) was used to achieve vehicle classification based on thermal image. Based on the limited data volume and quality, a classification accuracy of 97.7% was achieved. It shows the possibility of traffic monitoring system based on AI. If more learning data is collected in the future, 12-class classification will be possible. Also, AI-based traffic monitoring will be able to classify not only 12-class, but also new various class such as eco-friendly vehicles, vehicle in violation, motorcycles, etc. Which can be used as statistical data for national policy, research, and industry.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.1-12
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• 2021

Here, we introduce a laser-induced graphene synthesis technology and its applications for the electric/electronic device manufacturing process. Recently, the micro/nanopatterning technique of graphene has received great attention for the utilization of these new graphene structures, which shows progress developments at present with a variety of uses in electronic devices. Some examples of practical applications suggested a great potential for the tunable graphene synthetic manners through the control of the laser set-up, such as a selection of the wavelength, power adjustment, and optical techniques. This emerging technology has expandability to electric/electronic devices combined together with existed micro-packaging technology and can be integrated with the new processing steps to be applied for the operation in the fields of biosensors, supercapacitors, electrochemical sensors, etc. We believe that the laser-induced graphene technology introduced in this paper can be easily applied to portable small electronic devices and wearable electronics in the near future.