• 한국동물학회지
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• 제33권4호
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• pp.461-467
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• 1990

Acrylamide의 신경독성에 대해 조사하기 위하여 초기 후지마비 증상이 유도된 생쥐의 뇌를 SDS-PAGE와 이차원 전기영동법으로 분석한 결과, SDS-polyacrylamid gel 전기영동에 의해 처리군, 대조군 및 회복군을 비교하여 보았을때 두드러진 양상의 차이를 나타내지 않았으나 이차원 전기영동상에서 실험군간의 다소 상이한 단백질 양상이 관찰되었다. 특히, 처리군에서 spot 20(14,500, 5.64),21(19,900, 6.78)및 수개의 단백질이 소실되었으며 spot 9(31,300, 5.82),11(31,300, 5.36) 및 19(16,400, 5.42)들은 비교적 많이 감소되었다. 처리군에서 양적변화를 보인 이들 spot중에서 spot 20 (14,500, 5.64)는 회복군에서 대조군 보다 현저히 증가하였으나 spot 11(31,300, 5.36),19(16,400, 5.42) 및 다수의 spot들은 회복군에서 대조군과 대등한 양상을 보여주었다. 위와같은 실험결과는 acrylamide가 초기적 말초신경 장애를 나타내는 시기에 이미 뇌의 단백질대사에 관여함으로써 단백질합성이 저해되고, 이로 인하여 뇌의 조절능력이 부진하게 되어 결과적으로 중추신경계의 이상이 일어나게 된다는 것을 시사한다. 또한 손사에 대한 회복은투여된 농도 및 기간에 의존하여 acrylamide에 대한 노출이 중지된 후 점진적인 자구적 복구에 의해 이루어지는 것으로 사료된다.

• 펄프종이기술
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• 제40권3호
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• pp.23-29
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• 2008

This study was performed to improve the printability of Hanji using a microbial cellulose from Saprolegnia ferax through investigating the printability of Hanji sized with the mixture of the microbial cellulose and various kinds of sizing agents. Conclusions obtained from the results of this study were as follows. The proper concentration of a microbial cellulose in sizing a printable Hanji with it was 0.5%. In general, there was no remarkable effect but some effect on the opacity and ink density. Hanji was sized with the mixture(5:5) of microbial cellulose(0.5%) and AKD(1.0%). As a result, ink spread was remarkably improved by the girth reduction of ink spot. There was remarkable effect because the mixture(5:5) of a microbial cellulose(0.5%) and CMC(1.0%) improved not only the gloss but also the density and girth of ink spot. Mixing(7:3) with corn starch(3.0%) showed the smallest girth of ink spot among applied sizing agents. Mixing(7:3) with PVA(5.0%) also showed some effect in the density and girth of ink spot.

• 대한기계학회논문집A
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• 제27권5호
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• pp.705-712
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• 2003

Analysis for the thermal stress distribution in the laminated plates containing a hot-spot(local heating region) is performed. It is assumed that the local heating region induces only mechanical stress by the thermal expansion but effect of the thermal conduction is neglected. The region is regarded equivalent to a homogeneous inclusion expanding in a laminated medium. As an example, Au/YBCO/Al$_2$O$_3$laminate which is often employed for High Temperature Superconducting Fault Current Limiter(HTS FCL) has been analyzed. Effects of heat input, thickness of each layer and the got spot size upon the stress distribution in the hot-spot have been investigated. For a constant heat generation into the hot-spot, as the thickness of the Al$_2$O$_3$substrate increases, the stress in the YBCO layer is peculiarly oscillated, and the curvature of laminate has a maximum at a certain thickness of the Al$_2$O$_3$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.55-60
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• 2001

The automobile is made up of thousands of parts. Some parts are formed by pressing and combined by spot welding. To find weldability conditions of spot welding, clearance between two welding plates was made and after spot welding, weldability is evaluated by means of tensile shear load, nugget size and shape. Specimen used in this study was a steel plate of 1.2mm thickness and electrode was Cu-Cr alloy of 6mm diameter. When spot welding started, the clearance of two specimens was changed 0mm, 3mm and 5mm and distance from vise to measure influence of bending moment 25mm, 45mm, 65mm step by step. The fractured surface of specimen after this test was observed by Optical Microscope to measure microstructure and nugget shape. When clearance of two specimen was 3mm and 5mm, strength and nugget size was decreased and nugget shape was not clear. The much bending moment and crosshead speed are the much tensile shear load is.

• 대한임베디드공학회논문지
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• 제6권5호
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• pp.311-317
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• 2011

The blind spot is an area where drivers visibility does not reach. When drivers change a lane to adjacent lane, they need to give an attention because of the blind spot. If drivers try to change lane without notice of vehicle approaching in the blind spot, it causes a reason to have a car accident. This paper proposes a night-time blind spot vehicle detection using cameras. At nighttime, head-lights are used as characteristics to detect vehicles. Candidates of headlight are selected by high luminance feature and then shape filter and kalman filter are employed to remove other noisy blobs having similar luminance to head-lights. In addition, vehicle position is estimated from detected head-light, using virtual center line represented by approximated the first order linear equation. Experiments show that proposed method has relatively high detection porformance in clear weather independent to the road types, but has not sufficient performance in rainy weather because of various ground reflectors.

• 대한원격탐사학회지
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• 제24권5호
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• pp.483-496
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• 2008

Qualified ground control points (GCPs) are required to construct a digital elevation model (DEM) from a pushbroom stereo pair. An inverse geolocation algorithm for extracting GCPs from ERS SAR data and the SRTM DEM was recently developed. However, not all GCPs established by this method are accurate enough for direct application to the geometric correction of pushbroom images such as SPOT, IRS, etc, and thus a method for selecting and removing inaccurate points from the sets of GCPs is needed. In this study, we propose a method for evaluating GCP accuracy and winnowing sets of GCPs through orientation modeling of pushbroom image and validate performance of this method using SPOT stereo pair of Daejon City. It has been found that the statistical distribution of GCP positional errors is approximately Gaussian without bias, and that the residual errors estimated by orientation modeling have a linear relationship with the positional errors. Inaccurate GCPs have large positional errors and can be iteratively eliminated by thresholding the residual errors. Forty-one GCPs were initially extracted for the test, with mean the positional error values of 25.6m, 2.5m and -6.1m in the X-, Y- and Z-directions, respectively, and standard deviations of 62.4m, 37.6m and 15.0m. Twenty-one GCPs were eliminated by the proposed method, resulting in the standard deviations of the positional errors of the 20 final GCPs being reduced to 13.9m, 8.5m and 7.5m in the X-, Y- and Z-directions, respectively. Orientation modeling of the SPOT stereo pair was performed using the 20 GCPs, and the model was checked against 15 map-based points. The root mean square errors (RMSEs) of the model were 10.4m, 7.1m and 12.1m in X-, Y- and Z-directions, respectively. A SPOT DEM with a 20m ground resolution was successfully constructed using a automatic matching procedure.

• 한국식물병리학회지
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• 제11권3호
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• pp.282-284
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• 1995

Grey leaf spot on tomato plants was first observed in Sedo-myeon, Puyo-kun, Chungnam province of Korea in 1994. This disease which had not been reported before in Korea exhibited different symptoms from those of other leaf spot diseases on tomato plants. The symptoms were characterized by small irregular-shaped spots on leaves at the initial stage of the infection, subsequent spread and coalescence of the spots throughout the leaves with ultimate necrosis, and abscission from the plants. When healthy tomato plants were inoculated with a conidial suspension of the fungus isolated from the lesion of a diseased plant in a field, the same characteristic symptoms as those in the field were produced. Furthermore, the same pathogen could be reisolated from the lesions formed buy the inoculation. Conidial characteristics of the pathogen were as follows; oblong shape with constricted 3 transverse septa, round-shaped base, round- or point-shaped apex, size of 45~75$\times$12.5~17.5 ${\mu}{\textrm}{m}$, and 3.5 : 1 ratio of length to width. The pathogen was identified as Stemphylium lycopersici and thus this is the first report on the occurrence of grey leaf spot disease on tomato plants caused by s. lycopersici in Korea.

• 수산해양기술연구
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• 제49권4호
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• pp.352-359
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• 2013

To estimate the mesh selectivity of gillnet for ocellate spot skate (Okamejei kenojei), the field tests were carried out 12 times with six different mesh sizes (121.2mm, 137.7mm, 151.5mm, 168.3mm, 178.2mm, 189.4mm) in the coastal waters of Taean, Chungcheongnamdo of Korea, 2010~2011. In the field tests, the total number of species was 31, and that of catch was 1,410 and the total weight was 618,006g. The number and weight of ocellate spot skate which is main target in this study were 1,004 and 434,592g, respectively. The catch in number of ocellate spot skate occupied about 71.2% in total catch. The others of catch species were marbled sole (8.4%), sea raven (4.4%), japanese swimming crab (4.2%) and flatfish (4.1%) and so on. The range of body disk width (DW) of ocellate spot skates which were caught in this study was 15.2~35cm and the mode was 27~29cm. The estimation equation of mesh selectivity using the extended Kitahara's method was expressed as s $(R)=s(DW/m)={\exp}\{(-0.56R^3-1.80R^2+12.96R-9.99)-4.26\}$. The optimum value of DW/m for 1.0 of retention probability in this estimation equation was estimated 1.899 and DW/m was estimated to be 1.194, 1.314, 1.395, 1.461 and 1.520 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. When applied to the retention probability of 0.5, the optimum mesh size was estimated to be 177.0mm on first maturity disk width 26.9cm of ocellate spot skate.

• 한국항해항만학회지
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• 제28권5호
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• pp.385-393
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• 2004

본 논문에서는 변화하는 LNG 해운환경에 의한 3∼5년 이내의 Spot 시장 등장 가능성을 시스템다이내믹스 방법으로 분석하고, 이러한 가능성에 대한 하주인 가스공사의 전략적 대응방안을 모색하였다. 즉 하주와 해운선사가 상호 협력하여 국제적이고 자본집약적인 해운 및 조선 산업의 특징을 최대로 활용하면서 치열한 가능성에 대판 하주인 가스공사의 전략적 대응방안을 모색하였다 즉, 하주와 해운선사가 상호 협력하여 국제적이고 자본집약적인 해운 및 조선 산업의 특징을 최대로 활용하면서 치열한 국제시장에서 모두가 발전하고 미래의 LNG 및 LNG핀 Spot시장을 선점할 수 있는 전략과 이에 대응하기 위하여 필요한 선박 확보 방안으로 i) 하주가 직접 참여하는 방안, ii) 하주가 자회사를 통하여 참여하는 방안, 그리고 iii) 하주가 컨소시엄을 통하여 참여하는 방안을 제시하였다.

• Journal of Welding and Joining
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• 제19권4호
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• pp.379-383
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• 2001

Resistance spot welding has been widely used in the sheet metal joining processes because of low cost, high productivity and convenience. Recently, automobile and aerospace industries are trying to replace partly steel sheets with aluminum alloy sheets. But in the case of dissimilar materials, to apply resistance spot welding has been known to be very difficult owing to the effect of melting temperature. On this study, an effort was made to apply spot welding of dissimilar sheet metals, 2024 aluminum alloy and zinc coated steel sheet, evaluate the spot weld quality with tensile-shear strength test and nondestructive evaluation technique, C-scan image methodology. In this study results, as the current below 11 kA, melting of materials is not achieved well. Also as the current exceeds to 13.5 kA, the more spatters happen at welded zone and tensile-shear strength lowered. So, the feasibility of C-scan image technique proposed in the study is found to be suitable evaluation method for resistance spot weldability.