• 디자인학연구
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• 제17권1호
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• pp.383-392
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• 2004

본 연구의 목적은 우리나라에 유통되는 전동공구를 중심으로 사양과 디자인에 대한 비교를 통하여 각 제조사 디자인속성과 디자인 전략을 파악하는 것이다. 연구범위는 이 분야의 대표적인 3개 생산업체와 이들의 발전과정과 출시제품이며 연구방법은 각 제조업체의 제품 출시 수준(제품라인: product line)과 제품군별 다양화 수준(제품믹스: product mix)의 조사 비교, 그리고 이를 이미지 맵(image map)에 배치하여 디자인의 속성을 비교하는 것으로 했다. 전동공구는 동력원인 모터를 이용하여 각종 구조물을 제조ㆍ가공하는데 사용되는 공구로 구조적으로는 조립제품의 특징을 갖고 있고, 일반 사양은 소형, 경량인데다 견고한 제품속성과 함께 각 사양별로 규격과 종류가 다양한 것이 일반 소비재와 다른 점이다. 제품의 가장 중요한 요구조건이 사용 간편성과 우수성능이다. 이 때문에 장착 모터의 성능, 기어(gear)부의 정밀성, 내마모성 등이 전동공구의 품질을 좌우한다. 전동공구는 가정에서부터 중공업에 이르기까지 폭넓게 사용되고 있으며 기계, 자동차, 조선, 항공, 전자 공업 등 첨단 산업의 핵심 분야이다. 전동공구는 종류에 따라 전기 드릴 류, 전기 그라인더, 전기 톱, 전기샌더 등으로 구분할 수 있으며 사용자에 따라 산업용과 가정용으로 구분할 수 있다. 또한 작업용도별로 천공 작업용, 연삭 작업용, 연마 작업용, 체결 작업용, 절단 작업용으로 분류할 수 있다. 보슈(BOSCH), 블랙앤데커(BLACK&DECKER), 계양전기의 전동공구들을 제품라인과 제품믹스로 분류하여 각 업체의 제품특성을 비교하는 방법으로 이미지 스케일을 적용하였으며 이를 통하여 각 기업의 디자인개발 전략에 대하여 기초적 수준의 특성을 파악할 수 있었다. 이미지 맵의 파라미터는 각 업체별 제품의 컬러, 형태 및 하우징에 사용된 재료로 하였고 이를 통하여 디자인의 지향성을 비교분석할 수 있었다. 이에 부가적으로 동급제품을 각각 선정하여 이들의 성능에 대한 수평비교와 심층 분석을 통해 기술력, 품질, 성능 등의 차이점도 알아보았다. 비록 기초적 수준의 조사지만 이 과정을 통하여 전동공구의 시장의 일반 특성, 각 기업의 제품특성과 시장목표, 제품전략 등을 비교해 봄으로써 향후 전동공구 시장의 방향 예측과 디자인에 대한 개발전략의 기초 마련에 기여하고자 했다.

• 대한기계학회논문집B
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• 제34권4호
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• pp.349-354
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• 2010

연료전지는 환경문제와 천연자원 고갈을 해결할 수 있기 때문에 가장 주목받고 있는 새로운 동력원이다. 본 논문에서는 마이크로 연료전지의 효율을 높이기 위해 다양한 형상에 대해 마이크로 채널에서 수소가스 유동을 수치해석 하였다. 이미 개발된 채널과 새롭게 고안된 채널, 모두 여섯 개의 다른 형상을 가진 채널이 같은 유동 특성과 경계조건으로 수치해석을 수행하였다. 수치해석 결과를 통해 유속, 유동분포, 유동균일성 등이 채널형상에 따라 영향을 많이 받는 것을 알았다. 이에 수소 가스 유동을 고려한 채널형상 최적화를 통해 연료전지의 성능을 향상시키고자 하였다. 수치해석을 통한 최적화된 채널형상을 사용한 PEMFC 실험결과 평균보다 높은 전류밀도를 나타내었다. 그러나 내구성이 낮았다.

• 패션비즈니스
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• 제24권5호
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• pp.35-51
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• 2020

To satisfy consumers' desire to enjoy their own individuality and cultural trends, the discovery of various materials and the expression of materials embodying their characteristics are increasingly important in the fashion jewelry industry. This study examines, paper mulberry fiber, a raw material of hanji that has been excavated as a new material for fashion jewelry, is durable as wall as, soft and easy to form, has a unique texture along with, excellent aesthetic quality, and expresses various colors, thereby differentiating itself from traditional fashion jewelry materials. The material itself also has symbolic significance as an approach to discovering new sustainable materials for fashion jewelry to ensure increased specificity of the product based on the premise of freedom of expression. The weight and optimal drying time of chicken fiber were derived for the study of fashion jewelry expression using the characteristics of paper mulberry fiber. The techniques of casting, deflection, packing and winding (winding beads with fibers and straps) were derived and four brooches were produced in total. This study is meaningful for the future of, the fashion jewelry industry as it presents the uses of new materials such as paper mulberry fiber to induce multidisciplinary consumption and to suggest a direction for the creation of new value-added products. Further, in order to expand the realm of fashion jewelry industry with our own competitive products that have secured our cultural identity and uniqueness in the global market, there must be continued follow-up research on mass production methods for industrialization.

• 복식
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• 제56권7호
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• pp.1-17
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• 2006

This study purposed to examine Korean people's white clothes custom historically and to explain the aesthetic consciousness latent in the custom. Korean people preferred white clothes, even up to foreigners called them White-clad folk. Not only as in old historical literatures, but also in Soo-suh, Shin-Dang-suh including Sam-Kuk-Ji in China, white clothes were a real symbol to Korean people, ranging chronically far back to the age of ancient tribal countries, Sam-Kuk Period through Koryo Dynasty and even to modern age near the end of Chosun Dynasty, wearing with pleasure regardless of age, sex or social position. Even King himself in Koryo Dynasty is said to have worn white clothes when he was out of official hours. During the Koryo and Chosun Dynasty, white clothes were sometimes prohibited for various reasons including conflicts with the theories of yin-yang and the five elements but such regulations were not effective. To Korean people, white clothes were ordinary people's everyday dress as well as noble people's plain suits, saints' uniforms with religious meanings, ceremonial costumes, funeral garments, etc. The various uses show that white clothes have been worn by many people. The unique custom that a People have worn white clothes consistently for such a long time may contain very deep symbolic meanings representing the people's sentiments and spirits. The present study understood that the meanings come from religious sacredness, magical wish for brightness, the pursuit of purity originating from the people's national traits, assimilation with nature and the will to attain whole ascetic personality. Aesthetic attitudes based on aesthetic values summed up as sacredness, brightness, purity, assimilation with nature, asceticism, etc. are the aesthetic consciousness pursued by Koreans through their white clothes. For Koreans, white color is the origin of their color sense coming from primitive religions such as worshipping the sun and the heaven. In this way, Korean people's preference for white clothes began with primitive religions, was mixed with various social, cultural and religious influences and finally was settled as their durable spirit, symbol and beauty.

• 품질경영학회지
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• 제46권2호
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• pp.269-282
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• 2018

Purpose: The purpose of this study was to improve the FRP Van's durability by analyzing the problematic parameters, redesigning the rear van, and verifying the design drafts using the CAE analysis & Rig test. Methods: The collected data through the government quality inspection and field spot check were thoroughly analyzed through the characteristics diagram and the improvement suggestions were verified by performing CAE analysis, like the dynamic stiffness, Torsional stiffness, open/close condition's strength, Full car durability and Carrying out the actual test. Results: The results of this study are as follows; The output of CAE analysis shows that improvement suggestions have considerable effects on the reinforcement of FRP structure, and the actual torsion and open/close condition durability test prove that rear van may have durable life which is equivalent to vehicle life cycle. Conclusion: The structural weakness of KLTV's FRP rear van was overcome by applying the stiffener in rear van and changing the bonding method of each FRP pieces. That suggestions were proved using CAE analysis and Rig test.

• 한국도로학회논문집
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• 제12권3호
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• pp.103-111
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• 2010

에너지 절약과 $CO_2$발생량의 절감을 위해 자전거의 이용을 적극 장려하고 있다. 이를 위해 다량의 신설 자전거 도로 건설 계획을 추진 중에 있다. 현재 국내에서 신설 자전거도로 건설을 위해 아스팔트포장 및 콘크리트 포장을 비롯하여, 반강성포장, 유색포장, 흙포장 등이 적용되고 있다. 하지만 이들 포장형식은 자전거도로의 요구 성능에 비하여 시공비용이 높다. 본 연구에서는 경제적이고 친환경적이며 내구성을 확보한 자전거도로포장으로써 롤러 다짐 콘크리트의 최적 다짐율과 배합비를 기초물성시험을 통해 검토하였다. 도출된 배합비에 대한 동결융해와 제설제 저항성 시험을 통해 환경저항성을 검토하였다. 추가적으로 경제성 및 $CO_2$발생량을 일반콘크리트포장과 비교를 통해 평가했다.

• The Journal of Advanced Prosthodontics
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• 제12권5호
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• pp.273-282
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• 2020

PURPOSE. To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS. Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). RESULTS. The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION. Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

• Structural Engineering and Mechanics
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• 제64권2호
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• pp.243-257
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• 2017

Investigating the properties and durability of high-strength concrete exposed to sulfuric acid attack for the purpose of its application in structures exposed to this acid is of outmost importance. In this research, the resistance and durability of high-strength concrete containing macro-polymeric or steel fibers together with the pozzolans of silica fume or nano-silica against sulfuric acid attack are explored. To accomplish this goal, in total, 108 high-strength concrete specimens were made with 9 different mix designs containing macro-polymeric and steel fibers at the volume fractions of 0.5, 0.75, and 1.0%, as well as the pozzolans of silica fume and nano-silica with the replacement levels of 10 and 2%, respectively. After placing the specimens inside a 5% sulfuric acid solution in the periods of 7, 21, and 63 days of immersion, the effect of adding the fibers and pozzolans on the compressive properties, ultrasonic pulse velocity (UPV), and weight loss of high-strength concrete was investigated and the respective results were compared with those of the reference specimens. The obtained results suggest the dependency of the resistance and durability loss of high-strength concrete against sulfuric acid attack to the properties of fibers as well as their fraction in concrete volume. Moreover, compared with using nano-silica, using silica fume in the fibrous concrete mix leads to more durable specimens against sulfuric acid attack. Finally, an optimum solution for the design parameters where the crushing load of high-strength fibrous concrete is maximized was found using response surface method (RSM).

• Steel and Composite Structures
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• 제19권5호
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• pp.1115-1144
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• 2015

Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

• 한국환경과학회지
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• 제26권10호
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• pp.1155-1166
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• 2017

This study selected commonly known species of fruit trees, and re-selected the species that endure the stress of extreme cold weather and physiologically restore themselves to the previous state until the following year. Then we could go ahead to propose the species that were appropriate as urban greening plants in weather condition of any part of the country. To do this, we conducted an experiments for six species of fruit trees based on the preference of the general public and recommendation of the experts; Morus alba (English name: mulberries), Diospyros kaki (English name: Persimmon), Prunus persia (English name: Peach), Elaeagnus umbellata var. coreana (English name: Korean Autumn Olive), Malus domestica 'Alps Otome' (English name: Alps Otome), and Prunus mume (English name: Blue Plum). The experiment verifies whether the trees survive without any stress from the cold weather under the national climate conditions (one in the suburbs of Seoul: Yongin city, one in the central Chungcheong region: Daejeon city, and in the southern Gyeongsang region: Jinju city in Korea). The experiment lasted for a year from August 2016 to August 2017. The levels of electrolytic efflux, chlorophyll content, plant height, fresh weight, and dry weight were measured four times (on August of 2016, January, February, and August of 2017) for each tree planted bare ground outdoors. Results showed that Diospyros kaki, Prunus persia, and Malus domestica 'Alps Otome' were proven durable and resistant to winters of all three areas (one in the suburbs of Seoul: Yongin city, one in the central Chungcheong region: Daejeon city, and in the southern Gyeongsang region: Jinju city in Korea). Especially, the increase of chlorophyll content and the reduction of electrolytic efflux were noticeable in Prunus persia than in the other two species, proving itself as the most cold-tolerant among the six species used in the experiment. In addition, interpreting from the physiological restoration data of one-year span before and after getting through winterer, Prunus persia was proven to be the most cold-tolerant species.