• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.122-132
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• 2008

The purpose of this study is to present the basic materials of a developmental counterplan by assessing prevalence of musculoskeletal symptoms and characteristics of work-related ergonomic risk factors. The prevalence of musculoskeletal symptoms of 64 vineyard workers was investigated by using a self-reported questionnaire. And the vineyard workers' tasks were also collected and analyzed during 9-month period by observing and videotaping methods to identify the ergonomic risk factors. The prevalence rate of musculoskeletal symptoms of female(84.4%) was much higher than that of male(62.5%) and a total prevalence rate was 73.4%. There was no different prevalence of musculoskeletal symptoms between age over 60 years and under 60 years. The prevalence rates of musculoskeletal complaints for each body part were 48.4%, 42.2%, and 35.9% for the wrist, legs/knee, and shoulder, respectively. In postural risk analysis, 7 works(REBA score) represented the high risk tasks such as delivering harvest boxed(12), picking cluster(11) and so on. The main works(exposure score) were orderly ranked as picking cluster(1590), pruning branch(388), and cluster thinning(327). The risk factors of vineyard work were identified as follows: shoulder flexion(${\geq}45^{\circ}$), wrist Flex./Ext.(${\geq}15^{\circ}$), hand force(power/pinch-grip), and prolonged standing(${\geq}4hr$). The engineering solutions including an improvement of hand tools, working process, and working environment should be applied to the high risky tasks in order to resolve the ergonomic problems. The administrative solutions such as improving a distribution of resting time, an exercise cure, an early recognition of symptoms and rehabilitation might be another solution for reducing musculoskeletal symptoms in vineyard workers.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.105-112
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• 1979

Effect of gibberllin on the breaking of bud dormancy of root and growth of aerial parts were investigated under laboratory and field condition for the prolongation of shoot growth duration, shortening of fruit bearing age and the increase of root yield. Drop application of GA (0.5ml of 50ppm) on rhizome of one year old root broke bud dormancy better than by low temperature. Soaking for one hour of one year old roots which wintered in the field in GA (50-200ppm) greatly accelerated the emergence of new buds while kinetin was only effective at low level (50ppm). GA substantially increased stem length in early stage and petiole length later on while kinetin increased stem diameter. Under the field condition with polythylene film tunnel (PET) in early spring the soaking in GA (50ppm for 1 hour) of rhizome of 4 year old root with replanting and dropping GA (50ppm, 1ml) on rhizome without replanting brought earlier emergence (29days) in comparison with that in the usual field. PET alone caused 14 day-early emergence. GA increased the length of stem and petiole only in early stage and replanting decreased only petiole length in later stage. Soaking in GA with replanting caused the Pronounced decrease in peduncle length, percentage of (ruin set and dry weight of reproductive organ (fruits and peduncle). Dropping without replanting showed significant decrease only in dry weight of reproductive organ. Fruit maturing was 20 days earlier than in usual held with little difference between GA and PET. It is well expected that GA could be used for early emergence of bud, shortening of root dormancy period, thinning of fruit and higher root yield according to application amount and methods.

• Spatial Information Research
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• v.6 no.1
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• pp.77-90
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• 1998

The complex interactions of climate, topography, geology, biota and hwnan activities result in the land cover patterns, which are impacted by natural disturbances such as fire, earthquake and flood. Natural disturbances disrupt ecosystem communities and change the physical environment, thereby generating a new landscape. Community ecologists believe that disturbance is critical in determining how diverse ecological systems function. Fires were once a major agent of disturbance in the North American tall grass prairies, African savannas, and Australian bush. The major focus of this research was to develop stochastic model of spatial process of disturbance or spatial events and simulate the process based on the developed model and it was applied to the fire arrival process in the Great Victoria Desert of Australia, where wildfires generate a mosaic of patches of habitat at various stages of post-fire succession. For this research, Landsat Multi-Spectral Scanner(MSS) data covering the period from 1972 to 1994 were utilized. Fire arrival process is characterized as a spatial point pattern irregularly distributed within a region of space. Here, nonhomogeneous planar Poisson process is proposed as a model for the fire arrival process and rejection sampling thinning the homogeneous Poisson process is used for its simulation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.19-19
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• 2017

The indica ${\times}$ japonica rice (Oryza sativa L.) cultivars released in Japan since 1980 are high-yielding. However, occasionally in these cultivars their high yield potentials cannot be realized, particularly depending on climate conditions. The objectives of this study were to identify the reason for yield instability and the critical yield component factor causing lower grain yield in these high-yielding cultivars. Standard-yield japonica, high-yielding japonica-dominant, and indica-dominant cultivars were grown in western Japan. Rough grain yield (RY) in these high-yielding cultivars ranged from 450 to $980g\;m^{-2}$, and was positively correlated with potential grain yield (PRY). By fluctuations of solar radiation, RY changed with spikelet number (SNO), and SNO was correlated with cumulative radiation during the panicle formation period of 30 days before heading. Even if higher SNO was achieved under higher radiant conditions, RY was lower than PRY. The lower grain-filling in plants bearing higher SNO resulted from a lower filling percentage of spikelets (%F, RY/PRY), and %F was strongly correlated with spikelet fertility (%S) across all cultivars. %S was highly influenced by cumulative radiation per PRY during pollen development and establishment around heading. Inhibition of assimilation by leaf removal lowered %S. Conversely, stem thinning and removal of upper panicles around heading increased %S in spikelets of the lower part of the panicle in which sterility was higher. These results suggest that limitation of assimilate-supply due to low irradiance at the spikelet-formation and flowering stages restrains the potential of the high-yielding cultivars, depending on reduction of SNO and %S, respectively.

• The Korean Journal of Mycology
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• v.8 no.1
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• pp.7-11
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• 1980

To increase production of Tricholoma matsutake, experiments were carried out in a mountain located in Keumma 2-ri, Joocheon-myun, Yongwol-gun, Kangwon-do, Korea during the period from April to November 1979. The area of the experiment showed pH 6.55 of soil acidity and the rock was found to be granite. Among its vegetation, the major growths were Pinus densiflora Siebold et Zuccarini, Rhododendron mucronulatum Turcz., Rhododendron schlippenhachii Max., Lespedeza bicolor and Pteridium aquilinum (Linne) Kuhn var. japonicum Nakai. Of two equally divided areas of A and B in which pine mushrooms grew, artificial methods such as thinning the upper portion of land raking and water-spraying were applied to area B only, where 21% increase of the production was obtained as compared with the control area A.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.54-59
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• 1984

Research was conducted in a minirotation plantation with four different planting densities at Tatae-ri, Chongwoon-myon, Yangpyong-gun, Kyonggi-do, to investigate the relation between volume and biomass production. Nine-year-old Alnus hirsuta var. sibirica analyzed to determine volume yield and weight equations for aboveground parts. The results suggest that the most suitable harvesting or thinning period at highly dense plots, more than 6,000 trees per hectare, is five years after planting, and the most fitted regression equation model for estimating aboveground biomass or total tree biomass is $logY=b_0+b_1logd^2h$.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.476-486
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• 2018

In this study, the droplet size distribution, rheological properties, and stability of dairy cream-based emulsions homogenized with different sucrose fatty acid ester (SFAE, a non-ionic small-molecule emulsifier) concentrations (0.08%, 0.16%, and 0.24% w/w) at different homogenization pressures (10 MPa and 20 MPa) were examined. Homogenization at a high pressure resulted in a smaller droplet size and narrower droplet size distribution. The D[4,3] (volume-weighted mean) and D[3,2] (surface-weighted mean) values of the emulsions decreased with an increase in the SFAE concentration. The flow properties of the emulsions homogenized with SFAE showed shear-thinning (n=0.21-0.46) behavior. The apparent viscosity (${\eta}_{a,10}$) and consistency index (K) of the homogenized emulsions were lower than those of the control sample that is non-homogenized and without SFAE, and decreased with an increase in SFAE concentration. The storage modulus (G') and loss modulus (G") of all emulsions homogenized with SFAE were also lower than those of the control sample. The stability of all emulsions with SFAE did not show any significant change for 30 d at $5^{\circ}C$. However, the emulsions stored at $40^{\circ}C$ were unstable over the storage period. Therefore, the addition of SFAE enhanced the stability of dairy cream emulsions during storage at refrigeration temperature ($5^{\circ}C$).

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.210-221
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• 1998

In the period from the year 1500 to 1980. at least 14 large earthquake with epicenters in the northeastern China and Yellow Sea were felt or destructive in the Korean Peninsula. The most sigmificant events among them were the 1668 July 25 Tancheng earthquake of mamnitude 8.5, and the 1975 Feb. 4 Haicheng earthquake of magnitude 7.3. The Haicheng earthquake of the year 1975 in am extraordinary one among those occurred in the northeastern China in the 20th century in the sense the Shake of the event affected all over the Korean Peninsula. The tremor was felt even at the southeastern tip of the Korea and northern part of Kyushu 700km far away from the epicenter. In order to see the variation and trend of the effect of the Haicheng earthquake on the Korean Peninsula, the two data sets of the northern and southern parts of the peninsula were merged into one combined data set. The spatial variation of intensity shows smooth decrease from the value 4 of the northwestern region near the source to the value 1 of the Cheju Island and Kjushu. However, there are four regions of locally high intensity value. They are the region along downstream of Abrok(Yalu) River with intensity 5, the region around Shinpo of intensity 4, the area comprising Seoul and Chuncheon Cities of intensity 4, and Pohang-Pusan area of intensity 3. We suppose that there might be three types of possible mechanisms. The first one is concerned with the lateral inhomogeneity of velocity in the crust caused by wide distribution of relatively fractured rock. The second one is related with reflections of surface waves caused by the crestal thinning effect at border regions of the Peninsular in contact with the Ulleung Basin and the Japan Basin. The third possibility is local site effect caused by thick Tertiary or Quaternary rocks and soil layers.

• Journal of Mushroom
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• v.19 no.2
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• pp.96-102
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• 2021

A new cultivar of oak mushroom 'Dadam' was bred from monokaryotic strains of 'GMLE36062-4' and 'GMLE36288-34'. The optimum temperature for mycelial growth of the new cultivar 'Dadam' on potato dextrose agar was 19-22℃. Total cultivation period of the new cultivar, from innoculation to its first harvest, was 135-139 days, similar to that of the control cultivar 'Hwadam'. The pileus color and stipe thickness of the new cultivar were darker and thinner than those of 'Hwadam'. Total yield of 'Dadam' was 621 g per 3 kg substrate, and is higher than that of 'Hwadam' (371 g). In farmhouse field test, it showed that the period of mycelial growth, browning, and fruiting body formation were the same as those of the control cultivar L808. The number of available fruiting bodies of 'Dadam' was 15, and is lower than that of the control (47), therefore, it was possible to save workforce in thinning. The total yield for 2 flush was 480 g for 'Dadam', similar to the 473 g of the control cultivar.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.344-390
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• 1977

The purpose of this paper was to schedule optimum cutting strategy which could maximize the total yield under certain restrictions on periodic timber removals and harvest areas from an industrial forest, based on a linear programming technique. Sensitivity of the regulation model to variations in restrictions has also been analyzed to get information on the changes of total yield in the planning period. The regulation procedure has been made on the experimental forest of the Agricultural College of Seoul National University. The forest is composed of 219 cutting units, and characterized by younger age group which is very common in Korea. The planning period is devided into 10 cutting periods of five years each, and cutting is permissible only on the stands of age groups 5-9. It is also assumed in the study that the subsequent forests are established immediately after cutting existing forests, non-stocked forest lands are planted in first cutting period, and established forests are fully stocked until next harvest. All feasible cutting regimes have been defined to each unit depending on their age groups. Total yield (Vi, k) of each regime expected in the planning period has been projected using stand yield tables and forest inventory data, and the regime which gives highest Vi, k has been selected as a optimum cutting regime. After calculating periodic yields and cutting areas, and total yield from the optimum regimes selected without any restrictions, the upper and lower limits of periodic yields(Vj-max, Vj-min) and those of periodic cutting areas (Aj-max, Aj-min) have been decided. The optimum regimes under such restrictions have been selected by linear programming. The results of the study may be summarized as follows:- 1. The fluctuations of periodic harvest yields and areas under cutting regimes selected without restrictions were very great, because of irregular composition of age classes and growing stocks of existing stands. About 68.8 percent of total yield is expected in period 10, while none of yield in periods 6 and 7. 2. After inspection of the above solution, restricted optimum cutting regimes were obtained under the restrictions of Amin=150 ha, Amax=400ha, $Vmin=5,000m^3$ and $Vmax=50,000m^3$, using LP regulation model. As a result, about $50,000m^3$ of stable harvest yield per period and a relatively balanced age group distribution is expected from period 5. In this case, the loss in total yield was about 29 percent of that of unrestricted regimes. 3. Thinning schedule could be easily treated by the model presented in the study, and the thinnings made it possible to select optimum regimes which might be effective for smoothing the wood flows, not to speak of increasing total yield in the planning period. 4. It was known that the stronger the restrictions becomes in the optimum solution the earlier the period comes in which balanced harvest yields and age group distribution can be formed. There was also a tendency in this particular case that the periodic yields were strongly affected by constraints, and the fluctuations of harvest areas depended upon the amount of periodic yields. 5. Because the total yield was decreased at the increasing rate with imposing stronger restrictions, the Joss would be very great where strict sustained yield and normal age group distribution are required in the earlier periods. 6. Total yield under the same restrictions in a period was increased by lowering the felling age and extending the range of cutting age groups. Therefore, it seemed to be advantageous for producing maximum timber yield to adopt wider range of cutting age groups with the lower limit at which the smallest utilization size of timber could be produced. 7. The LP regulation model presented in the study seemed to be useful in the Korean situation from the following point of view: (1) The model can provide forest managers with the solution of where, when, and how much to cut in order to best fulfill the owners objective. (2) Planning is visualized as a continuous process where new strateges are automatically evolved as changes in the forest environment are recognized. (3) The cost (measured as decrease in total yield) of imposing restrictions can be easily evaluated. (4) Thinning schedule can be treated without difficulty. (5) The model can be applied to irregular forests. (6) Traditional regulation methods can be rainforced by the model.