• The Korean Journal of Ecology
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• 제24권6호
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• pp.385-394
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• 2001

An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

• 패션비즈니스
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• 제2권1호
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• pp.35-48
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• 1998

The purpose of this paper is to examine the street fashion, which is influenced by the youth culture in 1960s. Youth culture is the youth subculture which appeared multiform in the 1960s. It tried to create a new culture by subverting the ruling class culture with their combative life style and peculiar appearance which are distinguished from mother culture. Youth cultures as youth subculture are symbolically expressed in their style which had strong characteristics of sub-fashion and anti-fashion, and which are different from mother fashion in shape. Therefore youth subculture fashion had an effect on street fashion in the 60s. The influence that the youth culture fashion had had on the street fashion is summarized as follows: Beats fashion was intelligency look on black dress, black polo-neck shirts, black trousers, black glasses and heavy black eyeliner. Mods fashion was neat style on Edwardian suit with narrow trousers, pointer-toeshoes and smooth croped hair. Folkis fashion was ethnic look, middle east asian look, peasant look, Indian style, south america look, gypsy style, natural materials, natural dying, tie-dye, beads and hand made ornaments. Rockers fashion was violence appearance categorized 'blue collar' on black leather jacket decorated with metal studs and hand-painted insignia, blue jeans and boots for motor bike. Swinging London & the Psychedelics fashion was blend mods look with pschedelic color and motive pattern. Hippie fashion was intermix pschedelic and natural or ethnic style. It was appear to be a meaningless, unpredictable assortment of diverse items and style. Faded and tattered jeans, army jackets, vintage hat, beads, embroidered headband, white sheets, diverse theatrical costumes, sandals or bare feet, granny dress, peasant blouse, blanket cape, tie-dye T-shirts and long hair. Greasers fashion was adorned black leather jacket with chains, fringing, badges, insignia and sleeves had been crudely ripped off. They came to be known wore jeans so soaked with oil. Skinheads fashion was aggressive working class identity with donkey jacket, jeans rolled up, collarless union shirts, heavy boots, braces and hair cropped short.

• 한국의류학회지
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• 제43권6호
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• pp.866-876
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• 2019

This study examined the physiological and psychological effects of wearing gloves at rest in a cold environment. Seven elderly females participated in two separate trials: wearing gloves (WG) and bare hands (BH). The experiment was conducted for 60 min in a climatic chamber (air temperature 7.8±0.3℃ with 44±2%RH) with a sedentary posture. Microclimate temperature on the left palm was 4.16℃ higher in WG compared to that in BH (p<.1). Microclimate temperature on the chest during the last 5 min increased compared to the initial 5 min only in WG (p<.05). During the last 5 min, skin temperatures at the arm and hand in WG were higher than those in BH (p<.05). There was no statistical difference in the change of rectal temperature between WG and BH. Heart rate in BH was significantly higher compared to the WG (p<.05). Subjects also felt less cold on the whole body and hand in WG than those in BH (p<.05). The findings indicate that wearing gloves for elderly females affected the distribution of skin temperature and cardiovascular response in cold environments. Elderly females should be informed about the importance of wearing gloves through the clothing guideline in winter.

• Smart Structures and Systems
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• 제31권3호
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• pp.229-245
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• 2023

The absence of excitation measurements may pose a big challenge in the application of structural damage identification owing to the fact that substantial effort is needed to reconstruct or identify unknown input force. To address this issue, in this paper, an iterative strategy, a synergy of Tikhonov regularization method for force identification and modified Jaya algorithm (M-Jaya) for stiffness parameter identification, is developed for damage identification with partial output-only responses. On the one hand, the probabilistic clustering learning technique and nonlinear updating equation are introduced to improve the performance of standard Jaya algorithm. On the other hand, to deal with the difficulty of selection the appropriate regularization parameters in traditional Tikhonov regularization, an improved L-curve method based on B-spline interpolation function is presented. The applicability and effectiveness of the iterative strategy for simultaneous identification of structural damages and unknown input excitation is validated by numerical simulation on a 21-bar truss structure subjected to ambient excitation under noise free and contaminated measurements cases, as well as a series of experimental tests on a five-floor steel frame structure excited by sinusoidal force. The results from these numerical and experimental studies demonstrate that the proposed identification strategy can accurately and effectively identify damage locations and extents without the requirement of force measurements. The proposed M-Jaya algorithm provides more satisfactory performance than genetic algorithm, Gaussian bare-bones artificial bee colony and Jaya algorithm.

• Smart Structures and Systems
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• 제12권1호
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• pp.73-95
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• 2013

Nine deoxyribonucleic acid (DNA) sequences were used to functionalize single-walled carbon nanotube (SWNT) sensors to detect the trace amount of methanol, acetone, and HCl in vapor. DNA 24 Ma (24 randomly arranged nitrogenous bases with one amine at each end of it) decorated SWNT sensor and DNA 24 A (only adenine (A) base with a length of 24) decorated SWNT sensor have demonstrated the largest sensing responses towards acetone and HCl, respectively. On the other hand, for the DNA GT decorated SWNT sensors with different sequence lengths, the optimum DNA sequence length for acetone and HCl sensing is 32 and 8, separately. The detection of methanol, acetone, and HCl have identified that DNA functionalized SWNT sensors exhibit great selectivity, sensitivity, and repeatability with an accuracy of more than 90%. Further, a sensor array composed of SWNT functionalized with various DNA sequences was utilized to identify acetone and HCl through pattern recognition. The sensor array is a combination of four different DNA functionalized SWNT sensors and two bare SWNT sensors (work as reference). This wireless sensing system has enabled real-time gas monitoring and air quality assurance for safety and security.

• Corrosion Science and Technology
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• 제17권5호
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• pp.231-241
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• 2018

Atmospheric corrosion is generally an electrochemical degradation process of metal. It can be caused by various corrosion factors of atmospheric component, weather, and air pollutants. Moisture, particles of sea salts, and sulfur dioxide are major factors in atmospheric corrosion. Galvanizing coating is one of the most efficient ways to protect iron from corrosion by zinc plating on the surface of the iron. Galvanized steels are being widely used in automobiles, building structures, roofing, and other industrial structures due to their high corrosion resistance compared to bare iron. Atmospheric corrosion of galvanized steel has shown complex corrosion behavior depending on coating process, coating thickness, atmospheric environment, and air pollutants. In addition, different types and kinds of corrosion products can be produced depending on the environment. Lifespan of galvanized steels is also affected by the environment. Therefore, the objective of this study was to determine the corrosion behavior of galvanized steel under atmospheric corrosion at six locations in Korea. When the exposure time was increased, content of zinc from GA surface decreased while contents of iron and oxygen tended to increase. On the other hand, content of iron was constant even after 36 months of exposure of GI.

• Computers and Concrete
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• 제3권1호
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• pp.43-64
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• 2006

A tendon model that can effectively be used in finite element analyses of prestressed concrete (PSC) structures with bonded tendons is proposed on the basis of the bond characteristics between a tendon and its surrounding concrete. Since tensile forces between adjacent cracks are transmitted from a tendon to concrete by bond forces, the constitutive law of a bonded tendon stiffened by grouting is different from that of a bare tendon. Accordingly, the apparent yield stress of an embedded tendon is determined from the bond-slip relationship. The definition of the multi-linear average stress-strain relationship is then obtained through a linear interpolation of the stress difference at the post-yielding stage. Unlike in the case of a bonded tendon, on the other hand, a stress increase beyond the effective prestress in an unbonded tendon is not section-dependent but member-dependent. The tendon stress unequivocally represents a uniform distribution along the length when the friction loss is excluded. Thus, using a strain reduction factor, the modified stress-strain curve of an unbonded tendon is derived by successive iterations. The validity of the proposed two tendon models is verified through correlation studies between analytical and experimental results for PSC beams and slabs.

• 한국세라믹학회지
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• 제31권7호
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• pp.795-803
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• 1994

Ferroelectric BaTiO3 thin film was produced using BaTi-ethoxide sol. This sol was prepared from BaTi-ethoxide by a partial hydrolysis with ammonia as a basic catalyst and ethylene glycol as a chelating agent. BaTiO3 thin film was prepared from three continuous spin-coating layers of the sol on bare Si(100) wafer at 2500 rpm followed by pyrolysis at $700^{\circ}C$ for 30 min. After the heat treatment, the film was 0.200$\pm$0.010 ${\mu}{\textrm}{m}$ thick and its grain size was 0.059 ${\mu}{\textrm}{m}$. On the other hand, electrical properties were measured for BaTiO3 thin film separately prepared on Au-deposited silicon wafer. The dielectric constant and loss of the BaTiO3 thin film at room temperature was 150~160 and 0.04 respectively, which was measured at 10 kHz and oscillation level of 0.1 V. In the measurements of the dielectric properties at high temperatures, it was observed that the capacitance of the thin film increases steeply, while the dielectric loss reaches maximum around 1$25^{\circ}C$, which corresponds a phase transition from tetragonal to cubic BaTiO3.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.766-768
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• 2005

최근 대형 디스플레이 및 웨어러블 컴퓨터의 등장과 함께 키보드와 마우스를 사용하는 일반 데스크탑 환경에서 벗어난 컴퓨터와의 자연스러운 상호 작용 연구가 활발히 진행되고 있다. 본 논문에서는 스크린 정면에 놓인 프로젝터가 스크린과 그 위에 놓인 사용자의 손 위에 화면을 투영할 때 PC 카메라로 입력된 프레임 속에서 손의 영역을 인식하여 컴퓨터와 상호작용하게 하고자 한다. 이 경우에 투영된 빛이 사용자의 손 위에도 합쳐짐으로 인하여 피부의 고유색이 사라진다. 또한, 투영되는 화면이 사용자와 컴퓨터의 상호 작용에 따라 추정할 수 없이 변함에 따른 적응적 인식 방법이 필요하다. 따라서, 본 논문에서는 손을 인식하기에 앞서 스크린에 투영될 원본 이미지에 대해 칼라 보정을 수행하여 추정되는 카메라 입력 프레임을 생성한다. 이를 위해 우선 백색 영상을 투영하여 프레임 내의 자기 오차 맵을 생성한 후 R,G,B 채널 별로 원본 값에 대한 카메라 반응 값들을 룩업 테이블에 저장한다. 이를 통해 원본 이미지에 대해 칼라보정을 수행하고, 생성된 카메라 추정 프레임과 실제 카메라로 입력된 프레임 간 자기 성분을 비교하여 손 영역을 검출한다. 실험 결과, 주변의 조명 상태나 프로젝터 및 카메라의 위치에 관계없이 안정적인 인식 결과를 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.2064-2065
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• 2007

우리나라는 1960년대 이후 계속적인 경제성장에 따라 전력에너지의 수요도 끊임없이 증가하였고, 이후 꾸준한 전력계통의 설비 및 용량의 증가로 인해 현재에는 선진국 수준의 송전망을 구축하고 있으며, 765kV급 초고압 송전선로를 자체기술로 건설하여 운영하고 있는 상황이다. 향후 대용량 송전을 위한 초고압 송전계통 구성설비 증대가 계속 될 전망이다. 따라서, 전력의 신뢰도와 안전성 확보가 가능한 유지보수 방안이 필요 할 것이다. 특히 765kV 송전선로 고장시 전력계통에 미치는 영향은 막대할 것으로 사료되며 유지보수를 위해 휴전시 1일 수 억원의 발전제약비용이 발생 될 것으로 예상된다. 이에 765kV 송전선로의 휴전 없는 활선공법 활용의 필요성이 대두되고 있던 바, 산업자원부 전력산업연구개발사업으로 추진된 "초고압 송전선로 활선공법 및 관련장비 개발"(한국전기공사협회, 2006)과제가 성공적으로 개발되었고, 활선작업에서 중요한 직접활선작업원에 대한 전기적 안전성을 충분히 검토 분석되었다. (참고문헌 [1], [2], [3] 분석). 따라서 본 연구에서는 초고압 직접활선 기능을 보유할 수 있는 현장인력 양성을 위한 보다 효율적이고 안전한 교육 프로그램 개발 방안을 제시하고자 한다.