• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.724-729
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• 2004

The purpose of this study is to investigate the strength and ductility improvement of columns retrofitted with Fiber-Steel Composite Plate, compared with Steel Plate, and Carbon Fiber Sheet. Test specimens strengthened with 3 different materials--- carbon fiber sheet, steel plate and fiber-steel composite plate --- were tested under cyclic lateral force and a constant axial load equal to $20\%$ of the column's axial load capacity. The hypothetical equivalent value of the strengthening among three materials is introduced to evaluate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.749-751
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• 1998

In this study, the wind-mill type ultrasonic motor was fabricated, and then revolution and temperature characteristics of the ultrasonic motor were measured. Brass metal was pressed with umbrella-type using metal mold, then slot of 4 kind was processed in each of thickness. Among sixteen's ultrasonic motors, heat loss on applied voltage was much at stator of the highest resonant point, but heat loss on applied voltage was almost neglected at the lowest resonant point of stator. The thickener thickness of elastic body, revolution speed was decreased. The more slot of elastic body, revolution speed was increased. Applied voltage was changed from $10V_{max}$ to $100V_{max}$. When applied voltage was under $20V_{max}$, ultrasonic motor was not rotated. When applied voltage was over $90V_{max}$, revolution of ultrasonic motor was saturated. Maximum revolution speed was 510[rpm].

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.311-317
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• 2008

This study was carried out to improve our understanding about the influence of silt content on the stress-strain of sand under cyclic loading. Soil specimens were prepared by wet-tamping method as same void ratio and specimen's silt contents on total weights was changed from 0% to 20%. Also, effects of the silt contents on the stress-strain response were studied at different anisotropic consolidation ratio, Kc=1.0, 1.5, 2.0 condition. As a result, cyclic shear strength decreased as silt contents increased in same stress ratios. In same silt contents, cyclic shear strength increased as Kc increased in lower silt contents, but in higher silt contents, it had reverse results.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.321-322
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• 2004

Of the 20 arbitrarily chosen primers, six oligonucleotides decamer primers were used on the basis of the number of the polymorphisms generated in catfish (Silurus asotus) from Yesan and bullhead (Pseudobagrus fulvidraco) from Dangjin in Korea. Six primers were used generating a total of 602 scorable bands in catfish and 195 in bullhead population, respectively, ranging in size of DNA fragments from less than approximately 100 to larger than 2,000 base pairs (bp). Six primers yielded 199 polymorphic fragments (33.1 %) in catfish and 47 (24 %) in bullhead, respectively. In the present study, a total of 328 common fragments (an average of 54.7 per prime.) were observed in catfish population, whereas 84 (an average of 14.0 per prime.) in bullhead. The total number of specific fragments in catfish and bullhead population were 76and 64, respectively.

• 대한안전경영과학회지
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• 제16권1호
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• pp.139-146
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• 2014

As Crosby notes, the most companies spend 15 to 20% of their sales dollars on quality costs. Generally the most effective way to manage quality costs is to avoid having defects in the first place. In this paper we have studied about the repair(service) problem of domestic gas boiler within warranty period. We develop a system, which man could find the cause of the problem at an early stage and could devise a countermove to the problem under supposing that the service(repair) rate follows exponential distribution and the product is manufactured lot-for-lot continually. Using the developed early sensing system. it is expected to improve the reliability of the product, to save expenses of company and to improve customer's satisfaction. And the system will be expended to incorporate information technology, which can detect the repair rate automatically.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.52-52
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• 2010

선박건조에 있어서 대형 블록의 조립이 이루어지는 선행 탑재 및 탑재 단계에서 Tank Top과 Upper Deck의 V 개선 용접은 FCAW+SAW의 복합용접이 실시되고 있다. 그러나 가장 범용적 모재 두께인 18~20t의 경우 SAW 시공에만 약 5~6Pass가 소요됨으로써 다급한 진수 일정에 많은 지장을 초래하고 있다. 또한 능률 향상을 목적으로 용착량 증가효과를 얻기 위해 철분말이나 절선와이어를 개선면내에 충진하고 용접을 수행하나 획기적인 용접능률을 기대하기 어렵고 용접사 기량에 따라 용접 결함이 발생될 수 있다. 이에 따라 용접패스 수를 줄이고 결함 발생이 없는 용접기법 개발이 절실히 필요하였다. 이를 위해 매우 간단하고 효율적인 위빙장치를 제작하여 선탑/탑재 아래보기 용접이음에 1~2패스의 SAW 용접법을 개발하여 용접생산성은 물론 용접품질까지 획기적으로 향상시키는 기술 개발을 완료하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.165-170
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• 2011

A large number of seismic isolation systems have been developed since the early 1970s. They are basically a combination of elastomeric bearing and energy dissipators. The investigation described in this paper analyzes shear property and the frequency dependence of Lead Rubber Damper(LRD). Lead Rubber Damper is similar in shape and performance property to Lead Rubber Bearing. Experimental condition ranges from 20 to 200% in share strain and from 0.1 to 1.0Hz in frequency. When the shear strain is increased, effective stiffness and damping ratio are decreased. When the frequency is increased, change of the behavior characteristic is subtle.

• 생약학회지
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• 제20권2호
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• pp.83-87
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• 1989

The alkaloids of thirty five Korean plants which belong to Rhamnaceae, Sterculiaceae, Celastracea, Urticaceae and Rubiaceae were screened. Plant was extracted and solvent fractionated to yield ether soluble alkaloidal fraction and butanol soluble fraction. Each fraction was subjected to alkaloidal test by Dragendorff's reaction. The result showed eighteen plants strong positive, fourteen weak and six negative to alkaloidal test.

• 한국식품영양학회지
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• 제1권2호
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• pp.95-101
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• 1988

In order to produce lactic acid and calcium lactate very useful for foods and medical supplies, lactic acid fermentation was studied by Lactobacillus sporogenes, a spore forming lactic acid bacterium. When this bacterium was cultured aerobically in the spore forming medium, the spore forming rate was 96.0% as total cell number 20$\times$108/ml, spore number 19.2$\times$108/ml. One minute agitating every 1 hour in the flask culture, or agitation of 100rpm in the fermenter was most efficient to continue to ferment at 45$^{\circ}C$ for 4days in the fermentation medium containing 10% glucose as carbohydrate and CaCO3 as a neutralizing agent. This homofermentative lactic acid bacterium showed fermentation yield of 99.3% and more than 98.2% of the yield was L(+)-lactic acid.

• Ocean and Polar Research
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• 제23권1호
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• pp.1-10
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• 2001

Sea surface temperature derived from infrared images of NOAA satellites showed a warm eddy in the East Korean Bight(EKB) or Donghan Man during the winter 1997${\sim}$2000. To describe the warm eddy in the EKB, hydrographic data collected in 1934 and 1936 were also analyzed. The center of the warm eddy was located at about $39^{\circ}N$ and $129^{\circ}E$. The temperature and salinity of the eddy was about $4.0^{\circ}C$ and 34.0 psu, respectively, at 100m depth. The eddy rotated anticyclonically with a geostrophic current speed of about 20 cm/s. The mean state calculated from the data of 1922${\sim}$1960 showed the existence of a warm eddy over the EKB in winter. The eddy persists until late spring, and disappears from the previous location in summertime, only to be seen again in autumn.