• 한국멀티미디어학회논문지
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• 제22권5호
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• pp.626-637
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• 2019

Due to the rapid development of computer and digital technologies, those technologies were used in advertising. In order to meet the needs of marketing, a virtual space or character using 3D graphic augmented reality technology was developed and applied to advertisement. This study analyzed the characteristics of augmented reality in terms of interface design and spatial expression of augmented reality through case study. Firstly, we wanted to find the relationship between the types of the augmented reality advertisement and interface effects. Secondly, we wanted to find the spatial expression methods. The sample survey case studies based on 42 articles from 2012 to 2018 using Chinese and Korean site sharing augmented reality advertisement. The results of the case studies were divided into two parts. Firstly, the relationship between augmented reality types and interface effects were found basing on the augmented reality index. It means that the augmented reality index can be illustrated by using the augmented reality type. Simultaneously, the augmented reality type can be illustrated using the interface effect. The second part was that the types of display were used as a spatial representation. And the results showed that mobile display and public place display were the most frequently used.

• Geomechanics and Engineering
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• 제24권1호
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• pp.91-103
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• 2021

This paper concerns with forced dynamic response of thick functionally graded (FG) beam resting on viscoelastic foundation including porosity impacts. The dynamic point load is proposed to be triangle point loads in time domain. In current analysis the beam is assumed to be thick, therefore, the two-dimensional plane stress constitutive equation is proposed to govern the stress-strain relationship through the thickness. The porosity and void included in constituent is described by three different distribution models through the beam thickness. The governing equations are obtained by using Lagrange's equations and solved by finite element method. In frame of finite element analysis, twelve-node 2D plane element is exploited to discretize the space domain of beam. In the solution of the dynamic problem, Newmark average acceleration method is used. In the numerical results, effects of porosity coefficient, porosity distribution and foundation parameters on the dynamic responses of functionally graded viscoelastic beam are presented and discussed. The current model is efficient in many applications used porous FGM, such as aerospace, nuclear, power plane sheller, and marine structures.

• 한국해양공학회지
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• 제36권1호
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• pp.21-31
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• 2022

In recent years, various studies have been conducted on oscillating-water-column-type wave energy converters (OWC-WECs) with multiple chambers with the objective of efficiently utilizing the limited space of offshore/onshore structures. In this study, a numerical investigation based on a numerical wave tank was conducted on single, dual, and triple OWC chambers to examine the hydrodynamic performances and the energy conversion characteristics of the multiple water columns. The boundary value problem with the Laplace equation was solved by using a numerical wave tank based on a finite element method. The validity of the current numerical method was confirmed by comparing it with the measured data in the previous experimental research. We undertook a series of numerical simulations and observed that the water column motion of sloshing mode in a single chamber can be changed into the piston motion of different phases in multiple OWC chambers. Therefore, the piston motion in the multiple chambers can generate considerable airflow at a specific resonant frequency. In addition, the division of the OWC chamber results in a reduction of the time-dependent variability of the final output power from the device. As a result, the application of the multiple chambers leads to an increase of the energy conversion performance as well as a decrease of the variability of the wave energy converter.

• Advances in aircraft and spacecraft science
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• 제10권1호
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• pp.83-106
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• 2023

In this work, the static behavior of FGM macro and nano-plates under thermomechanical loading. Equilibrium equations are determined by using virtual work principle and local and non-local theory. The novelty of the current model is using a new displacement field with four variables and a warping function considering the effect of shear. Through this analysis, the considered sandwich FGM macro and nanoplates are a homogeneous core and P-FGM faces, homogeneous faces and an E-FGM core and finally P-FGM faces and an E-FGM core. The analytical solution is obtained by using Navier method. The model is verified with previous published works by other models and very close results are obtained within maximum 1% deviation. The numerical results are performed to present the influence of the various parameters such as, geometric ratios, material index as well as the scale parameters are investigated. The present model can be applicable for sandwich FG plates used in nuclear, aero-space, marine, civil and mechanical applications.

• 대한조선학회논문집
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• 제61권1호
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• pp.19-28
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• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• 한국수산과학회지
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• 제57권4호
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• pp.459-466
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• 2024

Digital color analysis was used to determine the gonadal maturity stages and levels of robust tonguefish Cynoglossus robustus specimens collected from the South Sea of Korea. Maturity stages were determined using photomicrographs depicting ovarian developmental phases and compared with digital color values. Speciments of C. robustus ranged in total length from 21 to 40 cm, with mature ovaries predominantly observed in specimens exceeding 30 cm in length. Monthly color values of the ovaries were primarily concentrated in the 1st and 4th quadrants of the color space, with a^* and b^* values ranging within ±20 and ±15, respectively. The color values of the testes were predominantly located in the 1^st and 4^sth quadrants, with a^* and b^* values ranging from -10 to 10 and -5 to 10, respectively. Although the color values of the mature and spawning stages overlap within a narrow range, distinguishing between them requires consideration of both color values and their monthly distribution. This study underscores the effectiveness of using digital color measurements over subjective visual assessments to evaluate the maturity of C. robustus gonads, thereby providing more quantitative insights into their reproductive biology.

• 수산해양기술연구
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• 제57권4호
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• pp.316-333
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• 2021

In order to understand basic data for improving the fishing system and fishing vessel structure in coastal improved stow net fishery, a questionnaire survey and on-site hearing were conducted from May 10 to June 11, 2019 to analyze opinions on the improvement of operation status and fishing vessel structure. The questionnaire survey consisted of ten questions on the operation status of coastal improved stow net fishery and six questions on the improvement of fishing vessel structure, and the results of each question were analyzed by the region, the captain's age, the captain's career and the age of fishing vessel. As a result of analyzing opinions on the operation status of the coastal improved stow net fishery, it was found that the average time required for casting net was 32.8 to 33.0 minutes and that the average time required for hauling net was 41.0 to 42.2 minutes which took 10 to 12 minutes more than for casting net. The most important work requiring improvement during fishing operation (the first priority) were 'hauling net operation,' 'readjustment and storage of fishing gear,' and 'fish handling' and the hardest factor in fishing management were in the order of 'reduction of catch,' 'labor shortage' and 'rising labor costs.' The most institutional improvement that is most needed in coastal improved stow net fishery was an 'using fine mesh nets.' Most of the respondent to the questions on the experience in hiring foreign crews was 'either hiring or willing to hire foreign crews,' and the average number of foreign crews employed was found to be 2.3 to 2.4 persons. The most important reason for hiring (or considering employment) foreign crews was 'high labor costs.' The degree of communication with foreign crews during fishing operation were 'moderate' or 'difficult to direct work.' The most important problem in hiring foreign crews (the first priority) was an 'illegal departure.' As the survey results on the opinion of structural improvement of coastal improved stow net fishing vessel, the degree of satisfaction with fishing vessel structure related to fishing operation was found to be somewhat unsatisfactory, with an average of 3.3 points on a five-point scale. The inconvenient structure of fishing vessel in possession (the first priority), the space needed most for the construction of new fishing vessel (the first priority) and the space considered important for the construction of new fishing vessel (the first prioprity) was a 'fish warehouse.' The most preferred equipment for the construction of new fishing vessel were 'engine operation monitoring' and 'navigation safety devices.' The average size (tonnage class), the average horse power and the average total length of fishing vessel for proper profit and safety fishing operation was between 13.8 and 14.0 tonnes, 808.3 to 819.5 H.P. and 23.4 to 23.5 meters, respectively. The results of the operation status of coastal improved stow net fishery and the requirement for improving the fishing vessel structure are expected to be provided as basic data for reference when we build or improve the fishing vessel.

• 한국조경학회지
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• 제30권2호
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• pp.70-78
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• 2002

The landscape disign of Gamcheon wholesale fish Market was designed around a turnkey base to promote the economy of Busan Metropolitan City, to establish a fishery marketing center and to modernize existing facilities. The objectives of the project were to promote the mood of an old market, while preserving its functions and efficiency as a market, to design outdoor spaces with natural resources and amenities in balance, and to create attractive tourist spots in connection with the wide area development plan. The project was oriented, fast, to enhance the functions of the market. For this purpose, a multi-dimensional space layout was designed in consideration of functions as a wholesale market. The safety of pedestrians was secured by separating lathes for vehicles and for pedestrians. Tree planting with various functions such as sheltering, wind breaking and guiding was planned. Secondly, nature-friendly and human-friendly landscaping design was attempted. For this, the beautiful natural resources of Amnam Park were utilized, and green spaces such as green bridges linking buildings in the wholesale market, and rooftop gardens were to be arranged. In addition, environment-friendly facilities such as roads paved with natural materials(i.e. gravel, shells) and program parking lots were to be planned. Thirdly, landscape design was considered to create attractive tourist spots. For example, a fish farm was created as a theme street for pedestrians and various water-friendly spaces such as pedestrian ramps, observatories and seaside streets were to be secured. The main contents are as follows. First, a green bridge to Ahnnam Park was introduced for a tour source and flower garden, an event plan and viewing deck open to the sea were planned on the bridge's axis. Secondly, for the effective land use plan concerning open space and convenience to visitors, a promenade was planned, which is connected with the theme plaza and small plazas by environmental sculptures in front of the market hall and at the gate. As well, an observatory and a roof garden help create three dimensional multi leveled space, with a good view of the natural landscape of the sea, sky and park Thirdly, landscape materials, such as trees and those for facilities, strengthened for protection against the seawind and salt damage were selected. The commercial market area was intended to be transformed a traditional functional area of efficiency and economy into an attractive marine leisure area where both tourists and neighbors can make use of it.

• 대한원격탐사학회지
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• 제29권4호
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• pp.389-397
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• 2013

최근 고해상도 영상레이더를 탑재한 위성이 성공적으로 발사, 운용되고 있다. 이들 위성에서 획득된 자료를 이용한 위상간섭기법의 활용은 다양한 지구과학적 분야에서 보다 자세한 정보를 제공하고 있다. 위상간섭기법 적용에서 긴밀도는 영상레이더 자료로부터 생성된 위상간섭도 질을 평가하는 매우 중요한 요소이다. 본 연구에서는 미국 서부 텍사스에 위치한 엘파소 지역에 대한 고해상도 X-밴드 TerraSAR-X(TSX), L-밴드 ALOS PALSAR와 중해상도 C-밴드 Envisat ASAR 위성 영상레이더 자료의 긴밀도 특성을 분석 평가하고자 한다. 짧은 시간기선거리(temporal baseline) 조건에서 X-밴드 TSX 자료의 긴밀도는 0.3~0.6으로 L-밴드 ALOS PALSAR 자료와 유사한 정도의 높은 긴밀도를 나타내었다. 이 수치는 C-밴드 Envisat ASAR 자료에 비해서는 상당히 높은 것이며 영상레이더 신호의 파장이 길수록 위상간섭도의 긴밀도 유지에 있어 보다 유리하다는 일반적인 산란 이론을 고려해 볼 때 의미있는 결과라 할 수 있다. TSX 자료가 높은 긴밀도를 갖는 이유는 안정적인 산란 특성을 잘 반영할 수 있는 높은 공간 해상력이 하나의 원인일 것으로 추정된다. 하지만 11~33일 정도의 짧은 시간기선거리에서는 비교적 높은 긴밀도를 유지하는 반면에 시간기선거리가 다소 길어질 경우 긴밀도가 크게 저하된다. 본 연구 결과를 통해 긴밀도가 시간기선거리와 매우 밀접한 관계에 있음을 확인할 수 있었다.

• 수산해양기술연구
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• 제56권4호
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• pp.347-360
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• 2020

In this study, the Bayesian state-space model was used for the stock assessment of the Blackfin flounder. In addition, effective measures for the resource management were presentedwith the analysis on the effectiveness of fisheries management plans. According to the result of the analysis using the Bayesian state-space model, the main biometric value of Blackfin flounder was analyzed as 1,985 tons for maximum sustainable yield (MSY), 23,930 tons for carrying capacity (K), 0.000007765 for catchability coefficient (q) and 0.31 for intrinsic growth (r). Also the evaluation on the biological effect of TAC was done. The result showed that the Blackfin flounder biomass will be kept at 14,637 tons 20 years later given the present TAC volume of 1,761 tons. If the Blackfin flounder TAC volume is set to 1,600 tons, the amount of biomass will increase to 16,252 tons in the future. Lastly, the biological effectiveness of the policy to reduce fishing effort was assessed. The result showed that the Blackfin flounder biomass will be maintained at 13,776 tons if the current fishing efforts (currently hp) level is set and maintained. If the fishing effort is reduced by 20%, it will increase to 17,091 tons in the future. The analysis on the economic effect of TAC showed that NPV will be the lowest at 1,486,410 won in 2038, 20 years after the establishment of 2,500 tons of TAC volume. If the TAC volume is set at 2,000 tons, NPV was estimated to be the highest at 2,206,522,000 won. In addition, the analysis on the economic effect of the policy to reduce the amount of fishing effort found that NPV will be 2,235,592,000 won in 2038, 20 years after maintaining the current level of fishing effort. If the fishing effort is increased by 10%, NPV will be the highest at 2,257,575 won even thoughthe amount of biomass will be reduced.