• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.305-316
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• 1997

A more efficient method for obtaining the fatigue life enhancement of a structure member with fastener holes is described. It is based on the combined process of cold-expansion and ring-indentation. Residual stresses were induced onto premachined holes using ring-indentation process near the fastener hole combined with cold-expansion. And residual stresses at the vicinity of a hole were evaluated using a fracture mechanics approach. The compressive residual stresses were larger using the combined process than is in the case of simple cold-expansion. Fatigue testing of aluminum specimens showed that the fatigue crack growth retardation emanating from a circular hole was greater for the combined process than for a simple cold-expansion alone.

• Journal of Astronomy and Space Sciences
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• v.39 no.2
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• pp.35-42
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• 2022

During their respective missions, the spacecraft Voyager and Cassini measured several Saturn magnetosphere parameters at different radial distances. As a result of information gathered throughout the journey, Voyager 1 discovered hot and cold electron distribution components, number density, and energy in the 6-18 Rs range. Observations made by Voyager of intensity fluctuations in the 20-30 keV range show electrons are situated in the resonance spectrum's high energy tail. Plasma waves in the magnetosphere can be used to locate Saturn's inner magnetosphere's plasma clusters, which are controlled by Saturn's spin. Electromagnetic electron cyclotron (EMEC) wave ring distribution function has been investigated. Kinetic and linear approaches have been used to study electromagnetic cyclotron (EMEC) wave propagation. EMEC waves' stability can be assessed by analyzing the dispersion relation's effect on the ring distribution function. The primary goal of this study is to determine the impact of the magnetosphere parameters which is observed by Cassini. The magnetosphere of Saturn has also been observed. When the plasma parameters are increased as the distribution index, the growth/damping rate increases until the magnetic field model affects the magnetic field at equator, as can be seen in the graphs. We discuss the outputs of our model in the context of measurements made in situ by the Cassini spacecraft.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.154-160
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• 1970

The present paper deals with the growth of yellow croaker by scale age reading. This study is based on material from 596 specimens caught by the Danish seine in the Yellow Sea during the period from June 1967 to April 1968. Ring marks of the scale were formed from April to July, corresponding to the spawning season of the fish reported by Bae (1960). Growth rate of each radius of the ring was approximately 0.73. The relationship between the total length and radius of scales, and the relationship between the body weight and total length are represented by the following equations respectively: L=61.350R+50.184 $$W=4.298L^{3.227}\times10^{-3}$$ Maximum total length calculated by the diagram of Walford's growth transformation, $$L_{n+1}=0.6866L_n+10.8730$$, was 346.9mm. Growth curve of the fish can be expressed by the following von Bertalanffy's equation : $$L_t=346.9(1-e^{-0.376(t+0.609)})$$

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.230-236
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• 2009

Growth status of the Littleneck calm Ruditapes philippinarum (Adams et Reeve) in Komso Bay was investigated by 600 individuals from February 2003 to January 2004. Based on the monthly variation of marginal growth rate of the shellfish, it was suggested that ring formation occurres between January and March once a year and takes approximately 19 months (1.58 old ages) to form a complete ring. The relationship between the shell height(SH) and the total weight(TW) could be represented by the following equation $TW=2.8{\times}\;10^{-3}SH^{2.3648}$. And the relationship between the shell height(SH) and shell length(SL) as well as the shell width(SW) were represented by equations SL=1.0027SH+5.812 and SW=0.5121H+1.2849 respectively. Growth curves for shell height and total weight fitted to the Bertalanffy's equation were expressed as $SH_t=42.83(1-e^{-0.4595(t-0.59)})$ and $TW_t=20.17(1-e^{-0.4595(t-0.59)})^{2.3648.}$

• Journal of the Korean Ceramic Society
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• v.25 no.6
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• pp.699-703
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• 1988

Domain structures of LiNbO3 crystals grown by Czochralski method were examined according to the growth axis and the rotational speed of crystals. Ring shape and split domain structures were revealed in Z-axis and Y-axis grown crystals respectively. It was found that the domain structures of grown crystals were closely related to the solid-liquid interface shape during growth.

• Korean Journal of Environment and Ecology
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• v.16 no.2
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• pp.149-159
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• 2002

Dwarf bamboo(Sasa borealis) is a dominant understory species in the various forest types in Korea. The objective of this study was to investigate vegetation structure of Sasa borealis and effects of Sasa on the growth of overstory tree species along the forest development after clearcutting. Three representative stand types with and without S. borealis in Baekwoonsan, Chonnam province were selected in 1998 for this study: uncutting stands(natural deciduous forests with overstory vegetation), 1987-cutting stands (11 years after clearcutting), and 1993-cutting stands(5 years after clearcuting). Vegetation type was largely classified into Sasa borealis dominant type and Sasa borealis recessive or absent type. The former composed of four associations including Quercus serrata-Carpinus laxiflora / Sasa borealis community, Cornus controversa-Morus bombysis / Sasa borealis community, Styrax japonica-Styrax obassia / Sasa borealis association, Zelkova serrata / Sasa borealis community. The latter divided into six associations including Quercus serrata / Lindera erythrocarpa community, Cornus controversa / Lindera erythrocarpa community, Quercus serrata / Acer pseudosieboldianum / Deutzia glabrata community, Fraxinus rhynchophylla-Quercus serrata / Lindera erythrocarpa / Euonymus alataus community, Rubus crataegifolius-Hydrangea macrophylla community, Rubus crataegifolius-Lespedeza bicolor community. Distribution of Sasa, borealis by developmental stages of forests showed that in natural stands was dominant understory, but was various pattern in two cutting stands. Mean annual ring growth of Quercus serrata and Carpinus laxiflora during the last 35 years had not been affected by presence of Sasa, based on comparisons in annual ring growth between Sasa-present and Sasa-absent stands. In conclusion, dense crown of Sasa borealis suppressed the invasion of other shrubs or annuals and facilitated later stages of plant succession by promoting growth of shade-tolerant tree species after clear cutting.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.408-423
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• 2021

We established and monitored survey sites in seven regions of Mt. Jiri to investigate population decline and change of the Korean fir (Abies koreana) over a ten-year period from 2009 to 2018. With the exception of one site (Seseok), the six remaining ones all showed a four-layer stratification structure. The importance value of Korean firs in all of the survey areas decreased significantly by 28.5%, from 55.7% in 2009 to 39.8% in 2018. The average population of objects with a diameter at breast height (DBH) of 5cm or more in all survey sites was 711 objects/ha in 2018, and the cumulative death rate from 2009 to 2018 was 10.8%. Among the death types, DS (dead standing) was the most dominant, comprising 82.4% of the total survey area. However, in Banyabong 1, which had a high gradient of 35°, the death types other than DS accounted for 44.2%. We estimate that A. koreana can maintain a stable population as its distribution type for each diameter class in the Saeseokpyeongjeon site showed a reverse-J shape. The average annual ring growth in all survey sites was 1.09 mm/year, with the most abundant growth observed in the Seseokpyeongjeon site, which was formed mainly by a subtree layer. The growth ring survey showed the estimated average age of A. koreana population in the Byeoksoryeong and Banyabong 1 sites to be 102 and 91 years, respectively, a general downward trend of vitality since 2013.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.16-20
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• 2010

Transplantation of matsutake-infected pine tree into a pine forest has great potential as an artificial cultivation method of Tricholoma matsutake. Matsutake-infected pine trees had previously transplanted by this research group into the experimental area from 2001 to 2004 and its survival rate determined in 2006 was 20%. For the survived samples, the characteristics of mycelial growth and the development of fairy-ring formation of T. matsutake have been evaluated until 2009. It was found that size of the indeterminate ring showed significant differences among the individual trees and varied from $4\;cm\;{\times}\;4\;cm$ to $52\;cm\;{\times}\;35\;cm$. The variation was possibly resulted from the differences in production area of the matsutake-infected pine tree and those in site characteristics of the transplanted spots. For the characteristics of mycelial growth, it grew in the shape of a cudgel or an acute-angled 'V' in early stage, and then the shape became more wider and changed into an obtuse-angled 'V' as time passed. We expect that matsutake mushrooms may occur from the fairy-rings of some of these matsutake-infected pine trees in the autumn of 2010.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.48-53
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• 1984

Using the Duff and Noland's method, the annual ring growth patterns of the red pine in the natural stands were examined at two locations; Seocheon, Chungnam-do where the stand had been infested with the pine needle gall midge, Thecodiplosis japonensis, during the years from 1975 to 1978, and Hongsong, Chungnam-do where had been no incidence of the insect damage. The results obtained are as follows: 1) With the normal red pine of 13 year old, the growth pattern in the oblique sequence indicates that the annual growth rates are maximum at the few terminal internodes, and decrease gradually with the downward internodes. Such characteristic of the growth pattern is not clear in the horizontal sequence of annual rings. 2) The indications of the radial growth reduction of the pine tree due to the pine gall midge infestation could be examined with any of three series at the crown level internodes; horizontal, vertical and oblique series. For the basal internodes, however, the horizontal series appeared to be inadequate for the analysis of the damage impact because it seemed to be masked by various factors other than direct effects of the damage. 3) Of the three ways of radial growth analyses, oblique sequence seems to be the most usefull, especially for the detection of the impact on growth caused by incipient or light infestation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.149-149
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• 2017

The RING (Really Interesting New Gene) finger proteins are known to play crucial roles in various abiotic stresses in plants. In this study, we report on RING finger E3 ligase, ${\underline{O}ryza}$ ${\underline{s}ativa}$ ${\underline{s}alt$-, ${\underline{A}BA}$- and ${\underline{d}rounght}$ stress-${\underline{i}nduced}$ RING finger ${\underline{p}}rotein{\underline{1}}$ gene (OsSAD1). In vitro ubiquitination assay demonstrated that unlike OsSAD1, a single amino acid substitution ($OsSAD1^{C168A}$) of the RING domain showed no E3 ligase activity, supporting the notion that the activity of most E3s is specified by a RING domain. Result of Yeast-Two hybridization, In vivo protein degradation assay supports that OsSAD1 interacting with 3 substrate, OsSNAC2, OsGRAS44 and OsPIRIN1, and mediates proteolysis of 3 substrates via the 26S proteasome pathway. Subcellular localizations of OsSAD1 while approximately 62% of transient signals were detected in cytosol, 38% of signals were showed nucleus. However, transiently expression of OsSAD1 was detected in cytosol 30% while as 70% of nucleus under 200 mM salt treated rice protoplasts. Results of bimolecular fluorescence complementation (BiFC) showed that two nucleus-localized proteins (OsSNAC2 and OsGRAS44) interacted with OsSAD1 in the both cytosol and nucleus. Heterogeneous overexpression of OsSAD1 Heterogeneous overexpresssion of OsSAD1 in Arabidopsis exhibited sensitive phenotypes with respect to Salt-, mannitol-responsive seed germination, seedling growth. In ABA conditions, OsSAD1 overexpression plants showed highly tolerance phenotypes, such as root length and stomatal closure. Our findings suggest that the OsSAD1 may play a negative regulator in salt stress response by modulating levels of its target proteins.