• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.95-104
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• 1976

This study was conducted to test the harvesting operation of two kinds of rice varieties such as Milyang #15 and Tong-il with a imported two furrow Japanese combine and was performed to find out the operational accuracy of it, the adaptability of this machine, and the feasibility of supplying this machine to rural area in Korea. The results obtained in this study are summarized as follows; 1. The harvesting test of the Milyang #15 was carried out 5 times from the optimum harvesting operation was good regardless of its maturity. The field grain loss ratio and the rate of unthreshed paddy were all about 1 percent. 2. The field grain loss of Tong-il harvested was increased from 5.13% to 10.34% along its maturity as shown in Fig 1. In considering this, it was needed that the combine mechanism should be improved mechanically for harvesting of Tong-il rice variety. 3. The rate of unthreshed paddy of Tong-il rice variety of which stem was short was average 1.6 percent, because the sample combine used in this study was developed on basisof the long stem variety in Japan, therefore some ears owing to the uneven stem of Tong-il rice could nat reach the teeth of the threshing drum. 4. The cracking rates of brown rice depending mostly upon the revolution speed of the threshing drum(240-350 rpm) in harvesting of Tong-il and Milyang #15 were all below 1 percent, and there was no significance between two varieties. 5. Since the ears of Tong-il rice variety covered with its leaves, a lots of trashes was produced, especially when threshed in raw materials, and the cleaning and the trashout mechanisms were clogged with those trashes very often, and so these two mechanisms were needed for being improved. 6. The sample combine of which track pressure was $0.19kg/cm^2$ could drive on the soft ground of which sinking was even 25cm as shown in Fig 3. But in considering the reaping height adjustment, 5cm sinking may be afford to drive the combine on the irregular sinking level ground without any readjustment of the resaping height. 7. The harvesting expenses per ha. by the sample combine of which annual coverage area is 4.7 ha. under conditions that the yearly workable days is 40, percentage of days being good for harvesting operation is 60%, field efficiency is 56%, working speed is 0.273m/sec, and daily workable hours is 8 hrs is reasonable to spread this combine to rural area in Korea, comparing to the expenses by the conventional harvesting expenses, if mechanical improvement is supplemented so as to harvest Tong-il rice. 8. In order to harvest Tong-il rice, the two furrow combine should be needed some mechanical improvements that divider can control not to touch ears of paddy, the space between the feeding chain and the thrshing drum is reduced, trash treatment apparatus must be improved, fore and rear adjust-interval is enlarged, and width of track must be enlarged so as to drive on the soft ground.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.9 no.1
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• pp.1-18
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• 1973

For regulating the depth of midwater trawl nets towed at the optimum constant speed, the changes in the shape of warps caused by adding a weight on an arbitrary point of the warp of catenary shape is studied. The shape of a warp may be approximated by a catenary. The resultant inferences under this assumption were experimented. Accordingly feasibilities for the application of the result of this study to the midwater trawl nets were also discussed. A series of experiments for basic midwater trawl gear models in water tank and a couple of experiments of a commercial scale gears at sea which involve the properly designed depth control devices having a variable attitude horizontal wing were carried out. The results are summarized as follows: 1. According to the dimension analysis the depth y of a midwater trawl net is introduced by $$y=kLf(\frac{W_r}{R_r},\;\frac{W_o}{R_o},\;\frac{W_n}{R_n})$$) where k is a constant, L the warp length, f the function, and $W_r,\;W_o$ and $W_n$ the apparent weights of warp, otter board and the net, respectively, 2. When a boat is towing a body of apparent weight $W_n$ and its drag $D_n$ by means of a warp whose length L and apparent weight $W_r$ per unit length, the depth y of the body is given by the following equation, provided that the shape of a warp is a catenary and drag of the warp is neglected in comparison with the drag of the body: $$y=\frac{1}{W_r}\{\sqrt{{D_n^2}+{(W_n+W_rL)^2}}-\sqrt{{D_n^2+W_n}^2\}$$ 3. The changes ${\Delta}y$ of the depth of the midwater trawl net caused by changing the warp length or adding a weight ${\Delta}W_n$_n to the net, are given by the following equations: $${\Delta}y{\approx}\frac{W_n+W_{r}L}{\sqrt{D_n^2+(W_n+W_{r}L)^2}}{\Delta}L$$ $${\Delta}y{\approx}\frac{1}{W_r}\{\frac{W_n+W_rL}{\sqrt{D_n^2+(W_n+W_{r}L)^2}}-{\frac{W_n}{\sqrt{D_n^2+W_n^2}}\}{\Delta}W_n$$ 4. A change ${\Delta}y$ of the depth of the midwater trawl net by adding a weight $W_s$ to an arbitrary point of the warp takes an equation of the form $${\Delta}y=\frac{1}{W_r}\{(T_{ur}'-T_{ur})-T_u'-T_u)\}$$ Where $$T_{ur}^l=\sqrt{T_u^2+(W_s+W_{r}L)^2+2T_u(W_s+W_{r}L)sin{\theta}_u$$ $$T_{ur}=\sqrt{T_u^2+(W_{r}L)^2+2T_uW_{r}L\;sin{\theta}_u$$ $$T_{u}^l=\sqrt{T_u^2+W_s^2+2T_uW_{s}\;sin{\theta}_u$$ and $T_u$ represents the tension at the point on the warp, ${\theta}_u$ the angle between the direction of $T_u$ and horizontal axis, $T_u^2$ the tension at that point when a weights $W_s$ adds to the point where $T_u$ is acted on. 5. If otter boards were constructed lighter and adequate weights were added at their bottom to stabilize them, even they were the same shapes as those of bottom trawls, they were definitely applicable to the midwater trawl gears as the result of the experiments. 6. As the results of water tank tests the relationship between net height of H cm velocity of v m/sec, and that between hydrodynamic resistance of R kg and the velocity of a model net as shown in figure 6 are respectively given by $$H=8+\frac{10}{0.4+v}$$ $$R=3+9v^2$$ 7. It was found that the cross-wing type depth control devices were more stable in operation than that of the H-wing type as the results of the experiments at sea. 8. The hydrodynamic resistance of the net gear in midwater trawling is so large, and regarded as nearly the drag, that sweeping depth of the gear was very stable in spite of types of the depth control devices. 9. An area of the horizontal wing of the H-wing type depth control device was $1.2{\times}2.4m^2$. A midwater trawl net of 2 ton hydrodynamic resistance was connected to the devices and towed with the velocity of 2.3 kts. Under these conditions the depth change of about 20m of the trawl net was obtained by controlling an angle or attack of $30^{\circ}$.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.43-54
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• 2001

This study was to investigate the behavior related to health, food habits, food consumption pattern and nutrient intakes of female students who residing in dormitory(self cooking) according to BMI(Body Mass Index). This study was carried out by questionnaired on June, 2000. Three hundred nine students were answered. The results were as follows: 1. The means of height, weight and BMI were 162.37$\pm$4.36cm, 52.48$\pm$5.54kg and 19.89$\pm$1.89. Under 20 of BMI among students were 53.1% and 20-25 of BMI were 46.9% of students. 2. In the self recognition of body shape, 63.4% of under weight subjects answered that their weight were normal. 73.1% of normal weight regard themselves more obese than their actual body shape normally shows. 51.2% of under weight subjects had attempted to control their weight. This results suggest that their weight control attempts were unnecessary. 3. 81.4% of subjects were answered irregular meals regardless BMI. 89.6% of subjects skipped breakfast. The main reasons were due to lack of time or not to eat proper food. Under weight subjects had less snack than normal weight subjects did(p '||'&'||'lt; 0.05). Normal weight subjects had more bun and cake than under weight subjects(p '||'&'||'gt; 0.05). 4. The consumption of vegetables and fruits were low regardless BMI. Mean energy, protein, Fe, Vit A, B$_1$, B$_2$, niacin, Vit C were above 75% of RDA, except calcium, in subjects. This study suggest that a comprehensive nutrition education program is need for college student in dormitory to improve their eating habits about skipping meal and breakfast and to increase the consumption of vegetables and fruits.

• Clinical and Experimental Pediatrics
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• v.49 no.9
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• pp.946-951
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• 2006

Purpose : The purpose of this study was to demonstrate the effectiveness of combined exercise for 12 weeks on the adiponectin and obesity related variables in overweight and obese children. Methods : Eighteen children in 5th grade in a certain elementary school in Busan were recruited. They were all overweight or obese children(more than 85 percentile in body mass index). Nine children in the experimental group were given exercises consisting of walking and band resistant training for 12 weeks. Auxological data(including height, weight and body fat mass) and laboratory data (fasting blood sugar, insulin, adiponectin) were checked at baseline and at the 1 week, and at the 4 weeks and 12 weeks stages of their exercise program. Insulin resistance and sensitivity were evaluated indirectly using HOMA index and QUICKI index. Results : Adiponectin gradually decreased until the 4 weeks point and gradually increased thereafter to the starting level at the 12 weeks stage. Body weight, body mass index(BMI) and HOMA index significantly decreased more at the 1 week, 4 weeks, and 12 weeks stages in the experimental group than in the control group. Body fat mass significantly decreased at 12 weeks. The change of insulin was significantly correlated with changes of body weight and BMI. But there was no correlation between changes of adiponectin and changes of insulin. Conclusion : Exercise seems to effect the adiponectin concentration. And it might be assumed that exercise increases the adiponectin concentration if it is continued for long time(may be more than 12 weeks). More studies may be necessary to draw that conclusion.

• Journal of Technologic Dentistry
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• v.10 no.1
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• pp.11-24
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• 1988

The purpose of this study was to determine the concentration of cadmium, nickel and chromium in the air of the work-place, blood of and urine of workers and compare the level of those heavy metals by the duration of work, work-place, process of work, smoking and other factors. In this study, 48 male dental laboratory technicans and 72 office workers as the control group were subjected. The concentration of cadmium, nickel and chromium in their blood sand urine, and that of heavy metals in the air of their work-rooms were examined and analyzed from June I 1987 to September 30, 1987. The results were as follows : 1. The concentration of cadmium in the air was the highest in the porcelain part, $0.0087{\pm}0.0016mg/m^3$, that of nickel was the highest in the crown bridge part, $0.4253{\pm}0.0052mg/m^3$, and that of chrnmium was highest in the partial denture part, $0.1063{\pm}0.0024mg/m^3$. 2. cadmium, nickel and chromium concentrations in the blood and urine of dental laboratory techincians were higher that in the office workers'. Especially the concentration of cadmium in the blood($1.92{\pm}1.23{\mu}g$/100ml) of th dental laboratory techician was about two times as high as that in the office workers'($0.90{\pm}0.73{\mu}g$/100ml), and the concentration of nickel in the urine($48.53{\pm}38.83{\mu}g$/e) of the dental laboratory thchnician was about two times as high as that in the office worker's($20.24{\pm}15.35{\mu}g$/e). 3. there was no difference in the concentration of cadmium, nickel and chromium in the blood and urine with a longer duration of work. 4. The concentration of cadmium and chromium in the blood and urine differed significantly depending upon the place of work. The concentration of cadmium was the highest in the blood of dental laboratory technicians working kin the poreclain part marking at $2.53{\pm}1.08{\mu}g$/100ml. The chromium level was the heighest in the blood of partial denture park workers with a concentration of $3.60{\pm}1.02{\mu}g$/100ml. Concerning the level of cadmium in urine, it was the highest in the porcelain part workers with a concentration of $3.41{\pm}3.15{\mu}g$/e. 5. The concentration of cadmium in the urine of metal trimming and polishing group($2.64{\pm}2.41{\mu}g$/e) was higher than that of non-metal trimming and polishing group($1.39{\pm}1.18{\mu}g$/e). 6. The concentration of chromium in the blood of smoking group($2.46{\pm}1.54{\mu}g$/100ml)was higher than that lf non-smoking group($1.54{\pm}1.25{\mu}g$/100ml). 7. The height positive correlation coefficient was shown between the concentration of nickel and chromium in the blood among the all correlations between 3metals(Cd, Ni, Cr) in the blood and those in urine. The correlation coefficient was relatively high(r=0.605,,p<0.01). In general, the higher the concentration of heavy metals in the air of work places the higher the concention lf them in the blood and urine of workers, mere attention should be paid to the working environment of dental laboratory workers, Furthermore, continuous biological monitoring and further research are required for an efficient health management for dental laboratory workers.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.97-104
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• 2007

This study was carried out to develop the modified cyclone dust collector in windowless broiler building measuring 12 m wide, 46 m long, with a side wall height of 3 m and a capacity of 12,800 birds. Ventilation rate in windowless broiler building was $0.014{\sim}0.015\;and\;0.158{\sim}0.181cmm$ in second weeks and fifth weeks of age, respectively. Ammonia concentration was $13{\sim}16\;and\;20{\sim}24\;ppm$ in first and second weeks of age, respectively. Amount of dust collected in dust collector each week was 104.1, 274.7 and 388.6g in first, second and third weeks of age. But it was decreased from fourth weeks of age because of the increased ventilation rate. Total suspended particulate(TSP) of polluted air was $3,111.7{\sim}8,745.2{\mu}g/m^3$, but it was decreased to $530.8{\sim}2,264.4{\mu}g/m^3$ when it passed through the dust collector. Collecting efficiency was $54.2{\sim}82.9%$ in TSP. But collecting efficiency of Particulate matter smaller than $1{\mu}g$ (PM1.0) was $7.6{\sim}33.8%$, and lower than TSP. TSP concentration in control broiler house was 1,387.6 and $4,210.1{\mu}g/m^3$ in first and fourth weeks of age, respectively. But it was decreased to 876.3 and $2,535.3{\mu}g/m^3$ in broiler house operated dust collector in first and fourth weeks of age, respectively. Dust collecting efficiency for TSP was $36.8{\sim}39.8%$, and it was decreased to $11.4{\sim}39.8%$ in smaller dust size.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.253-263
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• 2013

Frequency Scanning Interferometry(FSI) system, one of the most promising optical surface measurement techniques, generally results in superior optical performance comparing with other 3-dimensional measuring methods as its hardware structure is fixed in operation and only the light frequency is scanned in a specific spectral band without vertical scanning of the target surface or the objective lens. FSI system collects a set of images of interference fringe by changing the frequency of light source. After that, it transforms intensity data of acquired image into frequency information, and calculates the height profile of target objects with the help of frequency analysis based on Fast Fourier Transform(FFT). However, it still suffers from optical noise on target surfaces and relatively long processing time due to the number of images acquired in frequency scanning phase. 1) a Polarization-based Frequency Scanning Interferometry(PFSI) is proposed for optical noise robustness. It consists of tunable laser for light source, ${\lambda}/4$ plate in front of reference mirror, ${\lambda}/4$ plate in front of target object, polarizing beam splitter, polarizer in front of image sensor, polarizer in front of the fiber coupled light source, ${\lambda}/2$ plate between PBS and polarizer of the light source. Using the proposed system, we can solve the problem of fringe image with low contrast by using polarization technique. Also, we can control light distribution of object beam and reference beam. 2) the signal processing acceleration method is proposed for PFSI, based on parallel processing architecture, which consists of parallel processing hardware and software such as Graphic Processing Unit(GPU) and Compute Unified Device Architecture(CUDA). As a result, the processing time reaches into tact time level of real-time processing. Finally, the proposed system is evaluated in terms of accuracy and processing speed through a series of experiment and the obtained results show the effectiveness of the proposed system and method.

• Journal of Korean Society of Forest Science
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• v.76 no.2
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• pp.99-108
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• 1987

Half-sib seeds and one-year-old seedlings of Ginkgo biloba were treated with various simulated acid rains (pH 2.0, pH 3.0, pH 4.0 and pH 5.0) to examine the effects of acid rain on seed germination and seedling growth. The seeds were sown in a pot ($4500cm^3$) containing one of three different soils (nursery soil, mixed soil and sandy soil) and the seedlings were grown in the same pots as the seeds. Simulated acid rain was made by diluting sulfuric and nitric acid solution ($H_2SO_4$: $HNO_3$ = 3:1, V/V) with tap water and tap water (pH6.4), and treated by 5mm each time for three minutes during the growing seasons (April to October 1985 and April to August 1986). Acid rain treatments were done three times per week to potted seeds and seedlings by spraying the solutions. The seed germination, seedling growth and physiological characteristics of potted seedlings were compared among three soil types as well as among the various pH levels. The results obtained in this study were as follows: 1. Seed germination of Ginkgo biloba decreased significantly at pH 2.0 level in the field test, and also at the levels of both pH 2.0 and pH 3.0 in the laboratory test, compared to that at control. 2. For two-year-old seedlings, total, top and root dry weights per seedling were significantly different among the three soil types and among the levels of pH, and shoot growth was different only among the levels of pH. 3. For one-year-old seedlings, height and total and stem-branch dry weights per seedling were significantly different among the levels of pH.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.377-385
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• 2020

Recently, wheat consumption has been increasing in Korea, requiring increased production. Nitrogen fertilization is a critical determinant in crop yield; therefore, it is necessary to optimize the nitrogen fertilization regime with current trends that emphasize the minimum impact of nitrogen fertilizer on the environment. In this study, both nondestructive spectral analysis using a hyperspectral camera and growth analysis were performed to determine the optimal N top-dressing rates after heading. The nitrogen application regimes consisted of three conditions according to the secondary top-dressing rate: N_4:3:0 (0 kg 10 a^-1), N_4:3:3 (2.73 kg 10 a^-1), and N_4:3:6 (5.46 kg 10 a^-1). Subsequently, growth and physiological investigations were performed at the jointing, heading, and ripening stages of wheat, and spectral investigations were conducted. On April 29, as the nitrogen fertilization rate was increased to N_4:3:3 and N_4:3:6, plant height and grain yield increased by 4% and 8%, and 8% and 52%, respectively, compared to those under N_4:3:0. Leaf area index and SPAD value also increased by 13% and 24%, and 32% and 43%, respectively. The R (red), G (green), and B (blue) of leaf color were lowered by 15, 11, and 4 in N_4:3:3 and 44, 34, and 18 in N_4:3:6, respectively, as compared to the control. Grain yield was the highest at high top-dressing (N_4:3:6), however, there was no difference between no top-dressing (N_4:3:0) and intermediat top-dressing (N_4:3:3). The reflectance analyzed using a hyperspectral camera showed a difference in the near-infrared (NIR) region on March 19, and on April 29, there was a difference both in the visible light region greater than 550 nm and the NIR region. Vegetation indices differed according to fertilization regime, except for the greenness index (GI). The results of this study showed that not only growth and physiological analysis but also spectral indices can be used to optimize the nitrogen top-dressing rate.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.220-227
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• 2016

The objective of this research was to investigate the influence of application rates of dolomitic lime in the acid substrate on the mitigation of high bicarbonate damage in 'Seolhyang' strawberry. For this purpose, an acid substrate was formulated by mixing of sphagnum peat moss and pine bark with the ratio of 5:5 (v/v). The pH, EC and CEC of the substrate analyzed before application of dolomite were 4.07, $0.46dS{\cdot}m^{-1}$, and $91.3cmol+/kg^{-1}$, respectively. To adjust the pH of substrate, various amounts of dolomitic lime [$CaMg(CO_3)_2$] such as 0 (control), 1, 2, 3, and $4g{\cdot}L^{-1}$ were added during substrate formulation. Then, seedlings with 3 leaf stage were transplanted as mother plants and those were fed with Hoagland solution containing $240mg{\cdot}L^{-1}$ of the $HCO_3{^-}$. The growth parameters of mother plants 140 days after transplanting, such as plant height, chlorophyll content, and fresh weight were the highest in the treatments of 2 and $3g{\cdot}L^{-1}$ of dolomitic lime. The physiological disorders in mother plants were not observed in the 1, 2 and $3g{\cdot}L^{-1}$ treatments, but the symptoms of Ca, K and B deficiencies were observed in the 0 and $4g{\cdot}L^{-1}$ treatments. During the propagation period, the number of daughter plants derived from each mother plant were 21.0, 29.5, 35.8, 27.3 and 16.0 in the treatments of 0, 1, 2, 3 and $4g{\cdot}L^{-1}$, respectively. The substrate pH during cultivation of mother plants were maintained at appropriate levels for the 1 and $2g{\cdot}L^{-1}$ treatments, whereas it was the highest in $4g{\cdot}L^{-1}$ treatment. The contents of macro- and micro-elements in the above ground tissue were the highest in $2g{\cdot}L^{-1}$ and the lowest in $4g{\cdot}L^{-1}$ lime treatments. Above results suggest that the bicarbonate injury originated from ground water can be mitigated by adjusting the amount of dolomitic lime incorporated into the acid substrate.