• Journal of Advanced Marine Engineering and Technology
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• 제31권6호
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• pp.761-767
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• 2007

We have developed novel optical-fiber sensors based on strain-induced long-period fiber gratings for monitoring the deformation of a hull. They have no external pressure for sustaining the mechanical formed gratings. The pressure, which provides a force to form the periodic grating along the single mode fiber, was realized by the bonding strength of a photopolymer. To reduce the polarization dependency of the sensors caused by the asymmetry structure of gratings, a Faraday Rotator Mirror (FRM) was utilized in this experiment. We have realized the polarization-insensitive function of the proposed sensors. The change of an external strain are measured by an optical spectrum analyzer. When the external stain increases. the attenuation at the resonant wavelength decreases and the loss peak was slightly shifted to the shorter wavelength.

• 생명과학회지
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• 제11권3호
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• pp.254-258
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• 2001

The biochemical change during regeneration of perilla callus were investigated by comparing total protein and lipid contents, protein band pattern in SDS-PAGE, and fatty acid composition in the calli cultured for various period(0, 1, 3, 5 and 6 weeks) Calli were induced from cotyledon and hypocotyl explants of peplants of perilla on perilla on MS medium containing BA(0.5 mg/L) and NAA(0.5mg/L). The protein contents reached the peak at 3 weeks after induction of calli, and then was decreased. Total lipid contents was decreased as the culture period increased. The band pattern of polypeptides showed that 30KD and 45KD polypeptides and 22KD and 45KD polypetides were major proteins in the cotyledon and hypocotyl explants, respectively. However increase of culture period only 30KD protein was highly accumulated.

• 천문학회지
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• 제24권1호
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• pp.117-127
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• 1991

Here I report the confirmation of a long-term modulation of a period of $92^{+21}_{-13}$ years with the "time-delay correlation" method on the sunspot data compiled over the last a total of 289 years. This periodicity better specifies the cycle which falls pretty well within Gleissberg cycle, and clearly contrasts with the 55 year grand cycle which Yoshimura (1979) claimed. It is argued that the period-amplitude diagram method. which Yoshimura used, ana lysed peak amplitudes only so that a large number of data were disregarded, and thus was more susceptible to a bias. The planetary tidal force on Sun as for the possible cause to the solar activity was investigated and its possibility was ruled out in view of no period correlation between them.

• 해양환경안전학회지
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• 제21권4호
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• pp.449-456
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• 2015

본 연구에서는 다양한 감쇠판을 원통형 부유체에 부착하고 수치 시뮬레이션을 통해 원통형 부유체의 heave RAO 및 고유주기의 변화를 고찰하였다. 먼저 감쇠판을 부착하지 않은 원통형 부유체의 heave RAO 및 고유주기를 파악하였고, 원통형 부유체에 부착한 감쇠판의 크기와 형상을 바꿔가며 각 경우에 대한 heave RAO 및 고유주기를 평가하였다. 수치 시뮬레이션 결과, 감쇠판의 모든 면적에 대해서 감쇠판을 부착한 원통형 부유체의 고유주기는 증가하였고, 감쇠판의 크기가 1.30D부터 입사파의 피크주기에서 heave RAO는 감소하였다. 감쇠판의 모든 면적에 대해서 원형 감쇠판이 Y자형 감쇠판보다 고유주기가 길게 나타나며, 고유주기의 차이는 감쇠판의 면적이 커질수록 그 차이가 커졌다. 운동응답 스펙트럼 계산 결과, 원형 감쇠판과 Y자형 감쇠판을 부착한 원통형 부유체의 heave 운동이 입사파의 피크주기에서 현저하게 감소하였다. 또한 원형 감쇠판을 부착한 원통형 부유체의 고유주기가 Y형 감쇠판을 부착한 경우보다 입사파의 피크 주기에서 더 멀리 이동하였다.

• 대한치과교정학회지
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• 제15권2호
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• pp.197-209
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• 1985

To investigate the relationship between the pubertal spurt in body height and bone maturity of the hand-and-wrist in normal occlusion, the author X-rayed the hand-and-wrists of 1,141 students (male 614, female 527) and assessed their bone maturity. In this study, eleven skeletal stages were selected. The bones used to determine skeletal maturity were the ulnar sesamoid of the metacarpophalangeal joint of the first finger, the epiphyses of the proximal, middle, distal phalanges of the third finger, and middle phalanx of the fifth finger, and distal epiphysis of the radius. From the longitudinal data for height, an assessment was made of the change in growth velocity. The pubertal growth stage was divided into onset and peak height velocity phases. The results were as follows; 1. The onset of the pubertal growth was between the $PP_3=\;and\;MP_3=$ stage for boys, and between the $MP_3=\;and\;MP_5=$ stage for girls; the mean age of onset was 10.6 years for boys and 9.0 years for girls. 2. The peak height velocity was between the S and $MP_{3_{cap}}$ stage for boys, and between the $MP_{3_{cap}}$ and $MP_{5_{cap}}$ stage for girls; the mom age of peak height velocity was 12.5 years for boys and 10.9 years for girls. 3. As the stages of bone maturity progressed from $DP_{3u},\;to\;PP_{3u},\;MP_{3u}$, Ru, the peak height velocity had been reached, and the growth rate retarded, therefore the approach to full physical maturity was attained. 4. The evidence for the period of onset, peak height velocity and bone maturation suggested that girls were in advance of boys. During the latter part of pubertal growth, the rate of boys' bone maturation was faster than that of girls'.

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1361-1366
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• 2007

In this project, ovarian size and activity during the peak (November-April) and the low (May-October) breeding seasons in young and adult camels were studied. Ovaries of 92 camels (Camelus dromedarius), with clinically normal reproductive tracts, aged 3-15 years and slaughtered at Faisalabad or Lahore abattoirs over a period of 24 months, were collected. Jugular blood was collected from each animal before slaughter; the serum was separated and analyzed for oestradiol concentration. The size (length, width and thickness) and weight of each ovary were measured. Grossly observable Graafian follicles were counted and their diameter was measured using Vernier Calipers. The camels having ovaries presenting follicles more than 5 mm in diameter were taken as having active ovaries. The results showed that ovarian length, width and weight were significantly higher (p<0.05) during the peak than the low breeding season. The percentage of active ovaries was also significantly higher (p<0.01) during the peak than the low breeding season. However, the effect of season on ovarian thickness was non-significant. Similarly, the ovarian length, width, thickness, weight and activity did not vary significantly between young (3-7 years old) and adult (8-15 years old) animals. Serum oestradiol concentrations were significantly higher (p<0.05) during the peak ($67.70{\pm}1.36$ pg/ml) than the low breeding season ($15.25{\pm}1.54$ pg/ml). It was concluded that in Pakistani camels ovarian size and activity were higher during the peak than the low breeding season. However, age of the camel (from 3 to 15 years) had no effect on these parameters.

• Earthquakes and Structures
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• 제11권4호
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• pp.539-561
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• 2016

The rate of occurrence of intraplate earthquake events has been surveyed around the globe to ascertain the average level of intraplate seismic activities on land. Elastic response spectra corresponding to various levels of averaged (uniform) seismicity for a return period of 2475 years have then been derived along with modifying factors that can be used to infer ground motion and spectral response parameters for other return period values. Estimates derived from the assumption of uniform seismicity are intended to identify the minimum level of design seismic hazard in intraplate regions. The probabilistic seismic hazard assessment presented in the paper involved the use of ground motion models that have been developed for regions of different tectonic and crustal classifications. The proposed minimum earthquake loading model is illustrated by the case study of Peninsular Malaysia which has been identified with a minimum effective peak ground acceleration (EPGA) of 0.1 g for a return period of 2475 years, or 0.07 g for a notional return period of 475 years.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.29.4-30
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• 2010

A VHF meteor radar at King Sejong Station ($162.22^{\circ}S$, $58.78^{\circ}W$), Antarctica has been observing meteors during a period of March 2007-July 2009. We analyzed the height profiles of the observed meteor decay times between 70 and 95 km by classifying strong and weak meteors according to their estimated electron line densities. The height profiles of monthly averaged decay times show a peak whose altitude varies with season in the range of 80~85 km: higher peak in southern spring and summer than in fall and winter. The higher peak during summer is consistent with colder temperatures that cause faster chemical reactions of electron removal, as effective recombination rates measured by rocket experiments. The height profiles of 15-min averaged decay times show a clear increasing trend with decreasing altitude from 95 km to the peak altitude, especially for weak meteors. This feature for weak meteors is well explained by ambipolar diffusion of meteor trails, allowing one to estimate atmospheric temperatures and pressures, as in previous studies. However, the strong meteors show not only significant scatters but also different slope of the increasing trend from 95 km to the peak altitude. Therefore, atmospheric temperature estimation from meteor decay times should be applied for weak meteors only. In this study, we present the simple model decay times to explain the height profiles of the observed decay times and discuss the additional removal processes of meteor trail electrons through the empirical recombination and by icy particles.

• 한국수산과학회지
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• 제41권6호
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• pp.493-504
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• 2008

In the seas around the Korean Peninsula, the seasonal cycle of zooplankton related to North Pacific regime shifts was investigated to understand the reaction of the ecosystem to climate change using long-term data on zooplankton biomass (1965-2000) and the abundance of four major zooplankton groups: copepods, amphipods, chaetognaths, and euphausiids (1978-2000). In general, the zooplankton biomass showed a large peak in spring and a small peak in autumnin Korean waters, but there was a slight difference in the peak time depending on the location and the period before and after the North Pacific regime shift. The zooplankton biomass showed conspicuous seasonal peaks in R-III (1990-2000) compared to R-I (1965-1976) and R-II (1977-1988), and the seasonal peak shifted from the autumn in R-II to the spring in R-III. The peak of copepods and euphausiids in abundance was from April to June, while chaetognaths peaked from August to October. We postulate that the time lag between the peaks for copepods and chaetognaths results from the predator-prey relationship. The regime shift in 1989 did not alter the seasonal cycle of the four major zooplankton groups, although it enhanced their production. The seasonal peaks of the four major zooplankton groups did not shift, while the seasonal peaks of the zooplankton biomass did shift. This was not only becausethe zooplankton biomass included other mesozooplankton groups but also because the abundance of the four major zooplankton groups increased significantly in spring.

• The Korean Journal of Ecology
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• 제4권1_2호
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• pp.52-57
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• 1981

1969년이래 세계명국의 식물상화기형에 대한 연구를 하여왔다. 금번의 화기형은 화란, 독일, 불란서, 지중해연안, 희랍과 파레스타인의 식물상화기형을 밝힌것이다. 월별 화기율의 총화는 화란에서 독일, 불란서, 희랍, 지중해연안과 파레스타인의 식물상순으로 점차 증가현상을 보였다. 그리고 화기형이 2형으로 나누어지는 것을 볼 수가 있었다. 즉 화란, 독일 및 불란서와 같이 화기율의 월별 피-크가 7월에 나타나는 북온대형이 있고 지중해연안, 희랍 및 파레스타인과 같이 화기율의 피-크가 4월 또는 5월에 나타나는 지중해형이 있다. 북온대형은 주로 기온곡선과 관련이 큰점을 보게되고 지중해형은 특히 우량곡선과 큰 관련이 있는 것을 볼 수가 있었다.