• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.202-225
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• 2017

Non Timber Forest Products (NTFPs) has gained a lot of significance over the years as a means of income generation. Forests are playing a vital role in the supply of these products, however, due to their continuous extraction, the population of many species might have depleted. Very little information is known about community structure and population status of NTFPs. No specific studies have been made to find out the occurrence, availability of species and population status in the forests, supplying the resources. The present study has been carried out in community forests of the naturally occurring NTFPs in the temperate forest of the Ziro valley of Arunachal Pradesh. The main aim is to determine community structure, species composition and population status of NTFPs. Three forest stands viz., Nyilii, Dura and Gyachi were selected which are used by the Apatani tribe for extraction of the NTFPs. For evaluation of species composition and community characteristics, the sampling of the vegetation was done using the quadrat method. A total 137 species representing 68 families and 116 genera were recorded. Herbs represent the maximum diversity with 71 species followed by 35 shrub species and 31 tree species. The families Asteraceae and Rosaceaeae exhibited maximum representation followed by Urticaceae. The species under Fagaceae, Lauraceae, Rosaceae and Rutaceae were found to be important NTFP yielding species. Highest species richness was recorded in Nyilii having 124 species, while lowest in Dura with 102 species. Density of tree, shrub and herb ranged between 376 to $456\;individuals\;ha^{-1}$, 2848 to $3696\;individuals\;ha^{-1}$ and 31.44 to $36.64\;individuals\;m^{-2}$, respectively. The total basal area was found to be highest ($51.64m^2\;ha^{-1}$) in Dura followed by Nyilii ($25.32m^2\;ha^{-1}$) and lowest in Gyachi ($22.82m^2\;ha^{-1}$). In all the three study stands the species diversity indices showed the trend, herbs > shrubs > trees while the evenness index showed the trend as shrubs > herbs > trees. The overall species similarity index was highest (82.35%) between Dura and Gyachi. About 80% of the total recorded species showed clumped distribution while, no regular distribution was shown by any species. The three selected stands harbor about 50 important NTFP yielding species which are being used commonly by the Apatani people in their day to day life. Among the three study sites, overall diversity of NTFP was found highest in the Nyilii stand while the density of population was found better in Dura and Gyachi stands. The population of many species was found to be low due to continue harvesting without any sustainable management by the communities. All the selected forest stands have the potentiality to grow the high value NTFP yielding species and if managed properly, they can support the livelihood and economy of the local communities.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.361-368
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• 2015

This study was to investigate the effect of high energy diet on characteristics of Hanwoo steers distributed by estimated breeding value (EBV). The aim of this experiment was to determine the effect of high energy diet on the high and low beef group distributed by EBV for quality grades. We hypothesized that high energy diet is able to increase quality traits in high EBV groups when fed a high energy diet. A $2{\times}2$ factorial arrangement (High energy, control vs high EBV, low EBV) in a completely random design was used to feed 26 Hanwoo steers. Blood was drawn from each steers from 11 to 28 months. ADG and feed efficiency were not different between high energy and control diet (P>0.05). The level of DMI was greater at calf and early fattening diet in low EBV groups (P<0.05). Serum glucose and tryglyceride conecntrations were increased (P<0.05) by high EBV group from 22 to 28 month old. Serum NEFA concentration were plateau at 24 months at high EBV group and steady reduced by high energy diet (P<0.05). This data indicated that high energy diets increased serum glucose and triglyceride concentrations of high EBV steers at final fattening period.

• Journal of fish pathology
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• v.24 no.2
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• pp.53-64
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• 2011

In quantitative studies of clinical signs, rock bream of adults and juveniles infected with Megalocytivirus IVS-1 isolated from rock bream (Oplegnathus fasciatus) in Korea showed average $4.49{\pm}1.13$ and $4.85{\pm}1.06$ of spleen index respectively. In challenge experiments, Megalocytivirus IVS-1 induced 100% cumulative mortality in both adult and juvenile rock bream. However we found 60% cumulative mortality in juvenile red sea bream (Pagrus major) even after 30 days of injection, which contradicted with the results of other laboratories. Interestingly, IVS-1 infected red sea bream of the same juvenile size with rock bream showed lower spleen index compared to that of rock bream. In real-time PCR, there was continuous increasing of the numbers of viral copies ($2.03{\times}10^7$ copies/mg) in the spleen of juvenile rock bream infected, which were different from those in adult rock bream showing plateau level after reaching to the peak level. Moreover, enlarged cell numbers in the infected spleen were also increased continuously in the juvenile but not in adult of rock bream, even decreased after reaching to peak level. Consequently, significant differences in clinical signs: cumulative mortality. spleen index and viral copy number were found between rock bream and red sea bream, but not between adult and juvenile rock bream. Certainly quantitative expression of clinical sign as in this study may be a way to compare the progression of megalocitiviral disease more accurately in different species or physiological conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.3 no.1
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• pp.18-25
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• 1978

The 1/f noise spectrum of short-circuited output drain current due to the Shockley-Read-Hal] recombination centers with a single lifetime in homogeneous nondegenerate MOS-field effcte transtors with n-type channel is calculated under the assumptions that the quasi-Fermi level for the carriers in each energy band can not be defined if we include the fluctuation for time varying quantities. and so 1/f noise is a majority carrier effect. Under these assumptions the derived 1/f noise in this paper show some essential features of the 1/f noise in MOS-field effect transistors. That is, it has no lowfrequency plateau and is proportionnal to the channel cross area A and to the driain bias voltage Vd and inversely proportional to the channel length L3 in MOS field effect transistors. This model can explain the discrepancy between the transition frequency of the noise spectrum from 1/f- response to 1/f2 and the frequency corresponding to the relaxation time related to the surface centers in p-n junction diodes. In this paper the results show that the functional form of noise spectrum is greatly influenced by the functional forms of the electron capture probability cn (E) and the relaxation time r (E) for scattering and the case of lattice scattering show to be responsible for the 4 noise in MOS fold effect transistors. So we canconclude that the source of 1/f noise is due to lattice scattering.

• The Journal of Advanced Prosthodontics
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• v.1 no.3
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• pp.113-117
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• 2009

STATEMENT OF PROBLEM. Recently Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) has been introduced due to superior flexural strength and fracture toughness compared to other dental ceramic systems. Although zirconia has outstanding mechanical properties, the phenomenon of decrease in the life-time of zirconia resulted from degradation in flexural strength after low temperature aging has been reported. PURPOSE. The objective of this study was to investigate degradation of flexural strength of Y-TZP ceramics after various low temperature aging treatments and to evaluate the phase stability and micro-structural change after aging by using X-ray diffraction analysis and a scanning electron microscope (SEM). MATERIAL AND METHODS. Y-TZP blocks of Vita In-Ceram YZ (Vita Zahnfabrik, Bad $S\ddot{a}ckingen$, Germany) were prepared in 40 mm (length) $\times$ 4 mm (width) $\times$ 3 mm (height) samples. Specimens were artificially aged in distilled water by heat-treatment at a temperature of 75, 100, 125, 150, 175, 200, and $225^{\circ}C$ for 10 hours, in order to induce the phase transformation at the surface. To measure the mechanical property, the specimens were subjected to a four-point bending test using a universal testing machine (Instron model 3365; Instron, Canton, Mass, USA). In addition, X-ray diffraction analysis (DMAX 2500; Rigaku, Tokyo, Japan) and SEM (Hitachi s4700; Jeol Ltd, Tokyo, Japan) were performed to estimate the phase transformation. The statistical analysis was done using SAS 9.1.3 (SAS institute, USA). The flexural strength data of the experimental groups were analyzed by one-way analysis of variance and to detect statistically significant differences ($\alpha$= .05). RESULTS. The mean flexural strength of sintered Vita In-Ceram YZ without autoclaving was 798 MPa. When applied aging temperature at below $125^{\circ}C$ for 10 hours, the flexural strength of Vita In-Ceram YZ increased up to 1,161 MPa. However, at above $150^{\circ}C$, the flexural strength started to decrease. Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION. The monoclinic phase started to appear after aging treatment above $100^{\circ}C$. With the higher aging temperature, the fraction of monoclinic phase increased. The ratio of monoclinic/tetragonal + monoclinic phase reached a plateau value, circa 75% above $175^{\circ}C$. The point of monoclinic concentration at which the flexural strength begins to decrease was between 12% and 54%.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.225-233
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• 2010

Wind power density distribution over the North Korea territory was investigated by using 30-year wind observations at 27 meteorological stations. The mean annual wind power density over North Korea turned out to be 58.6W/$m^2$, which corresponds to the wind power class of 1. The wind power density shows a seasonal variation, having the highest density in spring and the lowest in summer. In particular, the wind power density in summer is about a half of that in spring. The diurnal variation of the wind power density shows that the highest and lowest densities occur in the afternoon and between 3 and 6 am in local time, respectively. The most potential wind energy generation regions are the Gaema Plateau in the central region, the northeast part of Hamgyeongbuk-do, the south coast of Pyongan-do and the west coast of Hwanghae-do. The mean annual wind power density in Changjin is 151.2W/$m^2$, which is equivalent to the class of 3. In Ryongyon, the annual mean wind power density is 102.4W/$m^2$, which belongs to the class of 2.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.115-123
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• 1978

Present status on the pesticides production, supply, manufacture and pests control in Korea are summarized. The data in the past several years (1971-76) are analyzed to find out the problems and solutions for the further development of plant protection and pesticide industry in Korea. Since the acreages of crop plantation and the quantities of pesticides uses are already near to the stage of plateau, pesticide formulation with imported technical grade should be modified by local synthesis with imported quality. The government pesticides management act and regulations must be modernized urgently in connection with the synthesis. formulation, tests, registration, quality control. price and supply system as well as the safety use of pesticides. Recommendation concerning acceptable daily intakes(ADI) and residue limits must be established for the strengthning pesticide safety use and plant protection activities as soon as possible. The use of fungicide-insectide mixture in dust formulation must be authorized and practiced immediately for the labor saving and one-hit cooperative mass control of rice disease and insect pests, especially. At present, serious considerations on pesticide safety use and integrated pest control are strongly urged to help the farmers, to save the industries and to keep the nature as it is required.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.91-97
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• 1994

To improve the productivity of peroxidase (POD) of cell line SP-47 derived from cell suspension cultures of sweet potato (Ipomoea batatas (L) Lam.cv White Star), we optimized culture conditions including the composition and concentration of plant growth regulators and carbon source, and the cell inoculum size. When one g (fr wt) of cells was inoculated into 50 mL TL medium supplemented with l mg/L 2,4-D and 30g/L sucrose in 300 mL Erlenmeyer flask at 25$^{\circ}C$ in the dark (100rpm), the POD activity per g cell dry wt was maximized to be about 6,800 units after 25 days of subculture, which was about 30 times higher than that of intact roots of horseradish plants grown in the greenhouse, but the cell growth was maximum after 15 days of subculture. The protein content per g cell dry wt maintained almost plateau and after 25 days of subculture decreased as culture Proceeded further whereas the POD specific activity (unit/mg protein) was about two times higher after subculture and continuously increased from 12 days to the end of cultures (40 days). The POD isozyme patterns showed almost the same regardless of cell growth stage, but some acidic isozymes were slightly increased after 25 days of subculture. These results indicate that POD activity in suspension cultures of sweet potato is closely associated with cell growth and stresses derived from cell culture renditions and medium depletion. Due to its high POD activity the SPL47cell line seems to be suitable for the mass production of POD.

• The Journal of the Petrological Society of Korea
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• v.5 no.1
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• pp.89-107
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• 1996

Sr, Nd and Pb isotopic characteristics of alkaline lavas and tholeiites in Cheju Island show that the isotopic compositions of the former slightly overlap, but have relatively more depleted than the latter. However, in viewpoint of the two eruptional stratigraphies of tholeiites, the isotopic compositon of the older one is similar to those of alkaline rocks in Lava Plateau Stage after Lee (1982). These suggest that the parental magmas of alkaline lavas and tholeiites might have originated from the homogenous mantle sourve and that the characteristics of the mantle source to be partially melted might be different between the eruption stages. The isotopic signatures of the bolcanic rocks in Cheju Island overlap with those in Samoa Islands and South China Basin, indicating the DMM-EM IImixing trend. This is distingushed from the DMM-EM I trend of the Cenozoic volcanic rocks in Korea except for cheju Island and Northeastern China. The modelled binary mixing calculation between MM and EM IImaterials indicates that the mantle source of the volcanic rocks in Cheju Island has been mixed about less than 10% of enriched mantle material (EM II) with depleted mantle material (DMM). Concerned with the indentation model between North China Block (NCB) and South China Block (SCB) after Yin an Nie (1993), we suggest that the distinct isotopic features of DMM-EM I and DMM-EM IIof the Cenozoic volcanic rock in Korea as well as China can be explained by the difference of the nature of subcontinental lithospheric mantle as enriched mantle materials, i.e. EM I of NCB, while EM II of SCB.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.395-404
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• 1995

The geologic structure of the Cheju volcanic island has been investigated by analyzing the gravity and magnetic data. Bouguer gravity map shows apparent circular low anomalies at the central volacanic edifice, and the maximum difference of the anomaly values on the island appears to be 30 mgal. The subsurface structure of the island is modeled by three-dimensional depth inversion of gravity data by assuming the model consists of a stacked grid of rectangular prisms of volcanic rocks bounded below by basement rocks. The gravity modeling reveals that the interface between upper volvanic rocks and underlying basement warps downward under Mt. Halla with the maximum depth of 5 km. Magnetic data involve aeromagnetic and surface magnetic survey data. Both magnetic anomaly maps show characteristic features which resemble the typical pattern of total magnetic anomalies caused by a magnetic body magnetized in the direction of the geomagnetic field in the middle latitude region, though details of two maps are somewhat different. The reduced-to-pole magnetic anomaly maps reveal that main magnetic sources in the island are rift zones and the Halla volcanic edifice. The apparent magnetic boundaries inferred by the method of Cordell and Grauch (1985) are relatively well matched with known geologic boundaries such as that of Pyosunri basalt and Sihungri basalt which form the latest erupted masses. Inversion of aeromagnetic data was conducted with two variables: depth and susceptibility. The inversion results show high susceptibility bodies in rift zones along the long axis of the island, and at the central volcano. Depths to the basement are 1.5~3 km under the major axis, 1~1.5 km under the lava plateau and culminates at about 5 km under Mt. Halla. The prominent anomalies showing N-S trending appear in the eastern part of both gravity and magnetic maps. It is speculated that this trend may be associated with an undefined fault developed across the rift zones.