• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.235-244
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• 2006

Granite cores were sampled within Korea Atomic Energy Research Institute and cyclic loadings up to 1550 cycles were applied. Microcrack development in samples due to cyclic loading was estimated using Acoustic Emission(AE) method. AE showed two different types depending on numbers of cycle. Type 1 appeared at low cycles and had low energy and diverse frequencies, while type 2 appeared at high cycles and had high energy and uniform frequency. AE property of type 1 indicates voids and pre-existing microcracks in samples may close or propagate up to certain length. Microcracks may be sheared or closed during loading and are recovered from shear or opened during unloading when AE of type 2 were measured. P wave velocities and Felicity ratios were measured at 50, 150, 350, 750, 1550 cycles. P wave velocities were almost the same regardless of number of cycles applied. However, Felicity ratios were much lower than 0.9, indicating that microcracks were developed within samples. This result indicates that Felicity ratio is a better tool than P wave velocity to estimate the damage of rock.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.3
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• pp.177-183
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• 1993

This study was conducted to obtain the transformed tobacco plants with S. cerevisiae Acid phosphatase gene(PH05) using Agrobacterium tumefaciens and th confirm plant transformation and gene expression. the results obtained were summarized as follows: APase activity of Saccharomyces cereviase NA 87-11A was remarkably showed up as deep red color when assayed by Tohe and Oshima(1974). PH05 fragment, Apase gene, was obtained from pVC727G and the graphically estimated size was about 1.5kb by agarose gel electrophoresis. The sequencing results of 5'end and 3'end of PH05 using dideoxy chain termination method were coinsided with the full length nucleotide already. pBKJ I vector was constructed by isolation of PH05 fragment from pVC727-1 and pBKSI-1 digesred with Sma I and Xba I. Isolated plasmid from transformed A. tumefaciens with constructed pBKJ I when it was electrophoresed with agarose gel. The dosc of tobacco leaf was cocultivated 재소 transformed Agronacterium tumefaciens. Transformed shoots were selected on kanamtcin-containing MS-n/B medium and they were regenerated. The transgenic tobacco plants were elucidated by isolation of genomic DNA and genomic southern hybridization using ${\alpha}-^{32}P$ labelled PH05 fragments. The PH05 in transformed tobacco plants was expressed in leaf, stem and root, and its APase activity was estimated as deep red color by Tohe method.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.37-42
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• 1984

This paper deals with the characterics of the stability of uncontinuous plate structures with cracks. The relation between the J-intergal of the cracks existing in the stress-concentrated regions and local strain are investigated experimentally and theoretically. The BEM(boundary element method)analysis and test results lead to the follow conclusions: 1. A non-dimensional J was computed in a plate stress and strain condition for several kind of loads and crack types. The J design curves are defined as follows: J sub(E)/$\sigma$ sub(y) super(2) a=3.345(e/e sub(y) ) super(2) at e/e sub(y)$\leq$1 J sub(E)/$\sigma$ sub(y) super(2) a=3.345(e/e sub(y) ) at e/e sub(y)$\geq$1 2. Use of this curve provides a good estimation for the uncontinuous plate structures with cracks existing in the stress and strain concentrated region. 3. The stability of the characteristics is mainly depenent upon not the length of cracks but the type of the cracks.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.2
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• pp.79-87
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• 2011

A fishing lamp is fishing gear to gather fish in the night. But the cost of oil which is used to a light fishing lamp, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnages. This cost has almost taken 30.40% of total fishing costs. As oil price increases, the business condition of the fishery gets worse and worse. Therefore, it is very urgent to develop an economical fishing lamp, to solve the problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery and hairtail angling fishery using the LED, which has excellent efficiency and durability. One fishing lamp has about 160Watt capacity and five fishing lamps are installed one aluminium panel in which sea water flows to emit generated heat from LED to outside. Developed fishing lamp lights to an effective direction of jigging and angling operation. This fishing lamp can be controlled to light the direction of fish shoal because the aluminium panel can be controlled to up and down direction. The wave length of fishing lamp has white and blue color. White color light is to gather fish shoal of horizontal direction and blue color light is to gather fish shoal of vertical direction. After development of this fishing lamp, 60.110 units are established on the boat, and operated fishing. Consequently, in the case of squid jigging, spent energy was reduced to 39%, in the case of hairtail angling, 68% of spent energy was reduced. And the catch was more than another boat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.253-259
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• 1981

A study was made to find out a new method of calculating the survival rate of a fish population from length composition and growth equation. 1. In the steady state of the fish population, let the total mortality rate be z, the age of complete recruitment a, the oldest age in the catch b and the average between the age of complete recruitment and the oldest age in the catch Ut, then we have $$U_{t}\;=\;\frac{a-b\;{e xp}\{-z(b-a)\}}{1-\;{e xp}\{-z(b-a)\}}+\frac{1}{z}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}$$(1) And let b be infinite, then we obtain $$Z=\frac{1}{U_t-a}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}$$ (2) 2. Calculating numerical value of $U_t$ from age composition table and growth equation, and substitute in (1) for it, we may obtain the value of z and $e^{-z}$. 3. This method is applied to a case of mackerel and horse mackerel in the coastal waters of Korea, with the following results : Total mortality rate-Mackerel : 0.87909, Horse mackerel : 2.22327, Survival rate-Mackerel : 0.41516, Horse Mackerel : 0.10825, 95 percent confidence Interval of survival rate-Mackerel : $0.35966{\sim}0.47264$, Horse mackerel : $0.06897{\sim}0.14974$

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1224-1232
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• 2020

Objective: The QingYu pig is well known for its excellent meat quality attributes in Sichuan province, China. In order to improve its production efficiency, the determination of genetic factors contributing to quantifiable economic traits of livestock is important. Moreover, the cross-breeding of QingYu pigs with western breeds possessing strong growth attributes is an efficient way to improve the performance of this breed. Methods: Here, the genetic parameters of several important reproductive traits of QingYu pigs were estimated, include total number born (TNB), number born alive, litter birth weight, individual birth weight, number of piglets weaned, litter weaning weight, and individual weaning weight. The data was analyzed using the ASReml 3.0 software (NSW Inc., Sydney, Australia). Furthermore, the effects of crossing Berkshire with QingYu (BQ) pigs on carcass and meat quality traits, as well as the effects of slaughter weight on carcass and meat quality of BQ were characterized. Results: QingYu pigs exhibited superior reproductive traits. The TNB available to QingYu pigs was more than 8 per parity. The observed repeatability of the reproductive traits of the QingYu pigs was between 0.10 and 0.23. The significantly correlated genetic and phenotypic of reproduction traits were consistent. Interestingly, the BQ pigs exhibited improved carcass quality, with a significant increase in loin muscle area, lean percentage and reduction in sebum percentage. As a result, BQ had higher L_45min, lower cooking scores, and lower drip loss. In addition, the loin muscle area, body length, and sebum percentage were significantly higher in 90 and 100 kg animals. Cooking loss showed a significant increase at 80 kg, and marbling increased significantly from 90 kg. Conclusion: The results of this study suggest that QingYu pigs exhibit excellent reproductive properties and heritability of these traits. Crossing with Berkshire is an efficient strategy to improve the carcass and meat quality of QingYu pigs for commercial operations. Furthermore, it appears as though the optimal slaughter weight of BQ pigs is at approximately 90 kg.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.253-258
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• 2005

The aim of this study was to estimate the time of ovulation and mating derived by plasma progesterone and estradiol-$17{\beta}$ concentrations. The 11 pregnant Shih-tzu bitches were investigated the plasma progesterone and estradiol-$17{\beta}$ concentrations from proestrus to parturition. Gestation length in the 11 pregnant bitches was $61.9{\pm}1.1\;(mean{\pm}SD)$ days when Day 0 was timed from the day that plasma progesterone concentration was first increased above 4.0 ng/ml. The litter size was $3.8{\pm}0.3$ pups. Plasma progesterone concentrations were increased at the first day of vulvar bleeding and showed at Day 0 with $5.2{\pm}0.3$ ng/ml. It was gradually increased to reach a peak at Day 15 with $42.6{\pm}3.7ng/ml$, thereafter it was gradually decreased to below Day 62. Plasma estradiol-$17{\beta}$ concentrations were increased above 1.0 pg/ml at the first day of vulvar bleeding and showed a peak at Day -2 with $33.5{\pm}8.0$ pg/ml, thereafter it was gradually decreased. When Day 0 was timed from the day that plasma progesterone concentration was first increased above 4.0 ng/ml, plasma estradiol-$17{\beta}$ concentration reached a peak at Day -2. In conclusion, these results indicated that ovulation was estimated to occur the day when plasma progesterone concentration was first increased above 4.0 ng/ml after the first day of bleeding. It was estimated that mating time was the day when plasma progesterone concentration was between $3.0{\~}8.0$ ng/ml.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.149-156
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• 2016

It has been well known that concrete structures exposed to chloride and sulfate attack environments lead to significant deterioration in their durability due to chloride ion and sulfate ion attack. The purpose of this experimental research is to evaluate the long-term durability against chloride ion and sulfate attack of the alkali activated cementless concrete replacing the cement with ground granulated blast furnace slag. For this purpose, the cementless concrete specimens were made for water-binder ratios of 40%, 45%, and 50%, respectively and then this specimens were cured in the water of $20{\pm}3^{\circ}C$ and immersed in fresh water, 10% sodium sulfate solution for 28, 91, 182, and 365 days, respectively. To evaluate the long-term durability to chloride ion and sulfate attack for the cementless concrete specimens, the diffusion coefficient for chloride ion and compressive strength ratio, mass change ratio, and length change ratio were measured according to the NT BUILD 492 and JSTM C 7401, respectively. It was observed from the test results that the resistance against chloride ion and sulfate attack of the cemetntless concrete were comparatively largely increased than those of OPC concrete irrespective of water-binder ratio.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.1-10
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• 2007

In general, the tension forces of hanger cable in suspension bridges play an important role in evaluating the bridge conditions. The vibration method, as a conventional one, has been widely applied to estimate the tension forces by using the measured frequencies on hanger cables. However, the vibration method is not applicable to short hanger cables because the fiequencies of short cables are severely sensitive to flexural rigidity. Thus, in this study, the tension forces of short hanger cables, of which the length is shorter than 10 meters, were estimated through back analysis of the cable fiequencies measured from Gwang-An suspension bridge in Korea. Direct approach to back analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method is able to search the optimal tension forces without regard to the initial ones and has a rapid convergence rate. To verify the feasibility of back analysis, the results from back analysis and vibration method are compared with the design tension forces. From the comparison, it can be inferred that back analysis results are more reasonable agreement with the design tension forces of short hanger cable. Therefore, it is concluded that back analysis applied in this study is an appropriate tool for estimating tension forces of short hanger cables.

• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.151-160
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• 2006

In this study, threshold runoff which is a hydrologic component of flash flood guidance(FFG) is estimated by using Manning's bankfull flow and Geomorphoclimatic Instantaneous Unit Hydrograph(GcIUH) methods on Han River watershed. Geographic Information System(GIS) and 3' Digital Elevation Model database have been used to prepare the basin parameters of a very fine drainage area($1.02\~56.41km^2$), stream length and stream slope for threshold runoff computation. Also, cross-sectional data of basin and stream channel are collected for a statistical analysis of regional regression relationships and then those are used to estimate the stream parameters. The estimated threshold runoff values are ranged from 2 mm/h to 14 mm/6hr on Han River headwater basin with the 1-hour duration values are$97\%$ up to 8mm and the 6-hour values are $98\%$ up to 14mm. The sensitivity analysis shows that threshold runoff is more variative to the stream channel cross-sectional factors such as a stream slope, top width and friction slope than the drainage area. In comparisons between the computed threshold runoffs on this study area and the three other regions in the United States, the computed results on Han River watershed are reasonable.