• Smart Structures and Systems
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• 제3권2호
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• pp.133-146
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• 2007

This paper addresses a new type of broad and stage-based hybrid carbon fiber reinforced polymer (HCFRP) sensor that is suitable for the sensing of infrastructures. The HCFRP sensors, a type of composite sensor, are fabricated with three types of carbon tows of different strength and moduli. For all of the specimens, the active materials are carbon tows by virtue of their electrical conductivity and piezoresistivity. The measurement principles are based on the micro- and macro-fractures of different types of carbon tows. A series of experiments are carried out to investigate the sensing performances of the HCFRP sensors. The main variables include the stack order and volume fractions of different types of carbon tows. It is shown that the change in electrical resistance is in direct proportion to the strain/load in low strain ranges. However, the fractional change in electrical resistance (${\Delta}R/R_0$) is smaller than 2% prior to the macrofractures of carbon tows. In order to improve the resistance changes, measures are taken that can enhance the values of ${\Delta}R/R_0$ by more than 2 times during low strain ranges. In high strain ranges, the electrical resistance changes markedly with strain/load in a step-wise manner due to the gradual ruptures of different types of carbon tows at different strain amplitudes. The values of ${\Delta}R/R_0$ due to the fracture of high modulus carbon tows are larger than 36%. Thus, it is demonstrated that the HCFRP sensors have a broad and stage-based sensing capability.

• Journal of Korea Trade
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• 제25권6호
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• pp.34-56
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• 2021

Purpose - This study presents strategies to overcome the COVID-19-induced crisis in Korea's meetings, incentives, conferences, and exhibitions (MICE) industry. It aims to quantitatively identify the environmental factors affecting the industry and their degree of influence, and derive optimal countermeasures. Design/methodology - The study applied the SWOT-AHP-TOWS framework. An AHP analysis was first performed within the SWOT frame, and then a TOWS analysis was conducted using the results of the SWOT-AHP analysis. In the AHP analysis, the number of pairwise comparison questions was limited to four for each SWOT factor to increase the consistency of responses by reducing the burden on respondents. Findings - The plunge in demand (threats factor) has had an overwhelming impact on the MICE industry, more than any other environmental factor. To overcome the crisis, the ST alternative that takes advantage of dynamic pop culture to minimize the business damage caused by the plunge in demand was the top priority measure. Based on the results, this study presents suggestions for overcoming the crisis in the MICE industry. First, the industry should develop profitable business models to supplement scarce financial resources by exploiting Korea's success with quarantine management. Second, the government must provide emergency relief funds or bailout support to protect MICE facilities and employees. Originality/value - Unlike previous work on the MICE industry, this study utilized the SWOT-AHPTOWS framework to derive quick research results in an abnormal situation. This approach can be expanded to other countries with different industrial environments and situations. Additionally, when applying this method to MICE sub-sectors, countermeasures should be tailored to each field.

• 산업융합연구
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• 제20권6호
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• pp.7-15
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• 2022

최근 4차 산업혁명 시대 도래에 따른 AI, 빅데이터 기술 발전으로 인해 신규 사업으로 떠오르고 있는 메타버스 산업이 부각되고 있다, 특히 이러한 관점에 본 논문은 메타버스 역사와 한국 메타버스 시장에서 가장 주목받고 있는 '제페토'의 장·단점을 분석함으로서 이를 기반으로 향후 발전해 나갈 수 있는 적절한 방향을 제시하고자 하였다. 본 연구를 수행하고자 먼저 초기 기업 분석방법으로 SWOT분석 기법을 활용하여 강점과 약점, 기회와 위협 요건을 살펴보고 각각에 요인현황을 도출하고자 하였다. 이후 도출된 각각의 요인들을 토대로 TOWS 발전전략을 모색하고 이를 기반으로 유의한 시사점을 제시하고자 하였다.

• 벤처혁신연구
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• 제4권1호
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• pp.87-99
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• 2021

코로나 19와 AI, 빅데이터, IT기술 발달 등과 같은 여파로 최근 '개인화 기술' 중요성이 부각되어지고 있으며, 이는 곧 개인화를 넘어 '초개인화 시대'에 도래하고 있다. 따라서 음원 스트리밍 서비스 시장측면에서는 개인 취향이 존중되는 서비스 공급 트랜드를 형성해 오고 있다. 이에 따라 기업들은 외부 시장 환경을 고려, 냉철한 분석을 토대로 발전방향을 수립하고자 하고 있다. 이러한 관점에 본 논문은 지니뮤직 고객 인터렉티브 전략에 기초하여 장·단점을 분석하고 기업 발전방향을 제시하고자 한다. 특히 고객과 함께 움직이는 '라이브음악서비스플랫폼'을 기반으로 고객 인터렉티브 전략 장·단점을 분석하고 이후 발전 방향을 제시하고자 하였다. 분석방법으로는 SWOT 분석 기법을 적용하여 강점과 약점, 기회와 위협 요건을 살펴보았다. 이후 TOWS 분석을 통해 구체적인 기업 발전전략을 제시하고자 하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.246-250
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• 2001

In resin transfer molding (RTM), resin is forced to flow through the fiber perform of inhomogeneous permeability. This inhomogeneity is responsible for the mismatch of resin velocity within and between the fiber tows. The capillary pressure of the fiber tows exacerbates the spatial variation of the resin velocity. The resulting microscopic perturbations of resin velocity at the flow front allow numerous air voids to form. In this study, a mathematical model was developed to predict the formation and migration of micro-voids during resin transfer molding. A transport equation was employed to account for the migration of voids between fiber tows. Incorporating the proposed model into a resin flow simulator, the volumetric content of micro-voids in the preform could be obtained during the simulation of resin impregnation.

• Fisheries and Aquatic Sciences
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• 제15권4호
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• pp.337-343
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• 2012

The Korean bottom trawl survey was conducted using a trawl designed by the National Fisheries Research and Development Institute (NFRDI). The capture efficiency and size selectivity of this trawl for snow crab Chionoecetes opilio was investigated by experimental tows. An auxiliary sampling net (underbag) was attached beneath the trawl net to capture crabs escaping under the trawl footrope. Experimental tows were made by the same vessel speed (3.4 knots) as in the bottom trawl survey, but toing time was shortened from the standard 30 min to 10 min to reduce possible trawl distortion due to the high catch rate of mud and debris in the underbag. In averaged over 17 tows conducted between 110-383 m depth, trawl efficiency of both males and females combined increased from about 10% at 20 mm (carapace width) to about 70% at 100 mm, with a width of 50% capture equal to 78 mm.

• Ocean Science Journal
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• 제40권1호
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• pp.11-16
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• 2005

Correction factors based on the catch ratios of egg and larval densities in the southern waters of Korea were estimated for anchovy Engraulis japonica. This was undertaken in order to adjust ichthyoplankton data from different sampling methods, gear types and time. Samples were collected during ichthyop1ankton surveys in Korean waters from 1983 to 1994. The ratios for egg densities obtained in vertical tows with a NORPAC net (ring $\Phi$, 45 cm) compared to those obtained in oblique tows with a KOB net (ring $\Phi$, 80 cm) were 0.86 (CV = 0.65), 1.22 (CV = 0.36), and 0.93 (CV = 0.42) for early, middle, and later developmental stages, respectively. The ratios for larval densities for vertical and oblique tows varied depending on size. For yolk-sac and small larvae (< 4 mm), the ratios were 3.08 (CV = 0.45) and 1.98 (CV = 1.34), while those of 4-6 mm, 6-8 mm, and 8-10 mm larvae were 0.44 (CV = 1.31), 0.45 (CV = 1.70), and 0.56 (CV = 2.50), respectively. Ratios of day/night densities for larvae of 4-10 mm lengths were lower (0.01-0.06) in offshore catches than values obtained in coastal areas (0.440.46) and similar values (0.16-0.04) for vertical and oblique tows. Our results indicated that vertical towing is more efficient for sampling early life stages (from eggs to larvae less than 4 mm long), while oblique towing is more efficient for larvae longer than 4 mm due to depth preferences for each developmental stage (e.g., changes in egg buoyancy and vertical migration oflarvae).

• 한국결정성장학회지
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• 제9권1호
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• pp.64-69
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• 1999

PANrP 탄소섬유의 고온연신에서의 변형 거동을 검토하기 위해서, 일정 하중하에서 내부저항 가열법에 의해 $1200^{\circ}C$부터 $2200^{\circ}C$까지 열처리 온도를 변화시키며 섬유의 strain 변화를 측정하였다. 부하된 응력이 증가함에 따라서 strain 변화가 크게 발생하며 또한 열처리 온도 약 $1700^{\circ}C$를 경계로 해서 그 온도 이상과 이하 사이에는 큰 차이를 보였다. 각 응력에 있어서의 strain 속도 변화로부터 얻어진 활성화 에너지는 70 MPa 및 322 MPa에 대하여 각각 67.46 및 52.27 kJ/mol로써, 큰 응력의 경우가 작은 응력을 부하하는 것 보다 섬유구조 발달에 있어서 더욱 효과적이라는 것을 알았다.

• 항공우주기술
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• 제9권2호
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• pp.73-79
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• 2010

본 연구에서는 비선형 유한요소 해석을 수행하여 굴곡도에 따른 유연직물복합재료의 등가 탄성계수를 예측하였다. 해석은 상용 유한요소 해석 프로그램인 ABAQUS를 사용하여 수행되었다. 해석에서는 섬유다발의 재료적 비선형성과 대변형 시 발생하는 기하학적 비선형성이 고려되었으며, 섬유다발의 대 전단 변형으로 발생하는 기하학적 비선형성을 고려하기 위하여 사용자 부프로그램을 작성하여 이를 ABAQUS내에 삽입하였다. 결과에서는 일축하중 상태에 있는 유연직물복합재료의 응력-변형률 거동을 예측하여 이로부터 계산된 등가탄성계수를 시험결과와 비교하였으며, 다양한 섬유 굴곡도를 갖는 유연직물복합재료에 대한 등가탄성계수를 계산하였다.

• 한국어류학회지
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• 제20권3호
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• pp.228-232
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• 2008

To investigate a proper sampling method for anchovy eggs and larvae in coastal waters of the South Sea, replicated samplings were made by different towing methods with different sampling gears and compared in terms of abundance and length composition. There was no significant difference in abundance in samples from vertical and oblique tows with a ring net. The abundance by replicated vertical tows with a ring net was not significantly different, but significant difference in abundance among sampling stations were found. The ring net sampled anchovy eggs in significantly greater numbers than collected by a NORPAC net, but both gears were not effective in obtaining quantitative samples of anchovy larvae larger than 3 mm. Therefore, samples by vertical tows with a ring net during the day at various stations is more efficient at estimating the density of anchovy eggs in an area compared to replicated sampling at a single station.