• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.126-132
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• 2010

A high sugar rice cultivar 'Danmi' which has been recently developed and released in the Functional Crop Resource Development Division, Department of Functional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed development. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of 'Danmi' and determined an optimum seeding rate for seedling establishment. 'Danmi' seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo's 26.7g. The 97.4% of 'Danmi' seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed germination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of $20-30^{\circ}C$ because of high seed amount of specific gravity below 1.0 in 'Danmi'. It took 2～4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. 'Danmi' has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of 'Danmi' in the seedbed was 62.6～64.9% for 10-day old seedling and 83.5～86.7% for 30-day old seedling which is lower by 29.6～30.0% and 11.3～12%, respectively than Ilmibyeo. Although 'Danmi' has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of 'Danmi' for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.461-470
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• 2019

This study was carried out to quantify the drought stress in grafted watermelon seedlings non-destructively by using chlorophyll fluorescence (CF) imaging technique rather than the visual judgment. Six-day old watermelon seedlings were grown under uniform irrigation for 3 days, and then given drought stress. Afterward, the sensor for the measurement of water content in plug tray cell unit was used to classify the drought-stress level into nine groups from D1 (53.0%, sufficient moisture state) to D9 (15.7%, extremely dry stress), and the 16 CF parameters were measured. In addition, re-irrigation was performed on the drought stressed seedlings(D5 - D9) to determine the growth and photosynthesis recovery level, which was not confirmed by visual judgment. The kinetic curve patterns of CF in three different drought stressed seedling groups were found to be different for the early detection of drought stress. All the 16 CF parameters decreased continuously with exposure to drought stress and drastically decreased from D5 (32.1%) where the visual judgment was possible. The fluorescence decline ratio (Rfd_Lss) started to decrease from the initial drought stress level (D5 - D6), and the Maximum PSII quantum yield (Fv/Fm) was significantly decreased in the later extreme drought stress range (D7 - D9) by re-irrigation recovery test. Thus, Rfd_Lss and Fv/Fm parameters were finally selected as potent indicators of growth and photosynthesis recovery in the initial and later stages of drought stress. Also, to the differences in the numerical values of the individual chlorophyll fluorescence parameters, the drought stress level was intuitively confirmed through the image. These results indicate that Rfd and Fv/Fm can be considered as potential CF parameters for the detection of low and extremely high drought stress, respectively. Furthermore, Fv/Fm can be considered as the best CF parameters for recovery at re-irrigation.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.102-109
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• 2019

Purpose: The purpose of this study was to evaluate the accuracy of three types of intraoral scanners and the accuracy of the single abutment and bridge abutment model. Materials and methods: In this study, a single abutment, and a bridge abutment with missing first molar was fabricated and set as the reference model. The reference model was scanned with an industrial three-dimensional scanner and set as reference scan data. The reference model was scanned five times using the three intraoral scanners (CS3600, CS3500, and EZIS PO). This was set as the evaluation scan data. In the three-dimensional analysis (Geomagic control X), the divided abutment region was selected and analyzed to verify the scan accuracy of the abutment. Statistical analysis was performed using SPSS software (${\alpha}=.05$). The accuracy of intraoral scanners was compared using the Kruskal-Wallis test and post-test was performed using the Pairwise test. The accuracy difference between the single abutment model and the bridge abutment model was analyzed by the Mann-Whitney U test. Results: The accuracy according to the intraoral scanner was significantly different (P < .05). The trueness of the single abutment model and the bridge abutment model showed a statistically significant difference and showed better trueness in the single abutment (P < .05). There was no significant difference in the precision (P = .616). Conclusion: As a result of comparing the accuracy of single and bridge abutments, the error of abutment scan increased with increasing scan area, and the accuracy of bridge abutment model was clinically acceptable in three types of intraoral scanners.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.246-254
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• 2022

Domestic facility agriculture grows rapidly, such as modernization and large-scale. And the production scale increases significantly compared to the area, accounting for about 60% of the total agricultural production. Greenhouses require energy input to create an appropriate environment for stable mass production throughout the year, but the energy load per unit area is large because of low insulation properties. Through the rooftop greenhouse, one of the types of urban agriculture, energy that is not discarded or utilized in the building can be used in the rooftop greenhouse. And the cooling and heating load of the building can be reduced through optimal greenhouse operation. Dynamic energy analysis for various environmental conditions should be preceded for efficient operation of rooftop greenhouses, and about 40% of the solar energy introduced in the greenhouse is energy exchange for crops, so it should be considered essential. A major analysis is needed for each sensible heat and latent heat load by leaf surface temperature and evapotranspiration, dominant in energy flow. Therefore, an experiment was conducted in a rooftop greenhouse located at the Korea Institute of Machinery and Materials to analyze the energy exchange according to the growth stage of crops. A micro-meteorological and nutrient solution environment and growth survey were conducted around the crops. Finally, a regression model of leaf temperature and evapotranspiration according to the growth stage of leafy vegetables was developed, and using this, the dynamic energy model of the rooftop greenhouse considering heat transfer between crops and the surrounding air can be analyzed.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.57-71
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• 2015

This study was conducted to develop the fertigation system with a peristaltic hose pump and brushless DC motor. The fertigation system was consisted of sensor, main controller, motor control unit, peristaltic pump, water supply pump, control panel, and filter. The peristaltic pump discharges liquid by squeezing the tube with rollers. Rollers attached to the external circumference of the rotor compresses the flexible tube. The fluid is contained within a flexible tube fitted inside a circular pump casing. The developed fertigation system has no mixing tank but instead injects directly a concentrated nutrient solution into a water supply pipe. The revolution speed of the peristaltic pump is controlled by PWM (Pulse width modulation) method. When the revolution speed of the peristaltic pump was 300rpm, the flow rate of the 3.2, 4.8, 6.3mm diameter tube was 202, 530, 857mL/min, respectively. As increasing revolution speed, the flow rate of the peristaltic pump linearly increased. As the inner diameter of a tube larger, a slope of graph is more steep. Flow rate of three roller was more than that of four roller. Flow rate of a norprene tube with good restoring force was more than that of a pharmed tube. As EC sensor probe was installed in direct piping in comparison with bypass piping showed good performance. After starting the system, it took 16~17 seconds to stabilize EC. The maximum value of EC was 1.44~1.7dS/m at a setting value of 1.4dS/m. The developed fertigation system showed ±0.06dS/m deviation from the setting value of EC. In field test, Cucumber plants generally showed good growth. From these findings, this fertigation system can be appropriately suitable for fertigation culture for crops.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.164-171
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• 2022

Frankliniella occidentalis is an invasive pest insect, which affects over 500 different species of host plants and transmits viruses (tomato spotted wilt virus; TSWV). Despite their efficiency in controling insect pests, pesticides are limited by residence, cost and environmental burden. Therefore, a fixed-precision level sampling plan was developed. The sampling method for F. occidentalis adults in pepper greenhouses consists of spatial distribution analysis, sampling stop line, and control decision making. For sampling, the plant was divided into the upper part(180 cm above ground), middle part (120-160 cm above ground), and lower part (70-110 cm above ground). Through ANCOVA, the P values of intercept and slope were estimated to be 0.94 and 0.87, respectively, which meant there were no significant differences between values of all the levels of the pepper plant. In spatial distribution analysis, the coefficients were derived from Taylor's power law (TPL) at pooling data of each level in the plant, based on the 3-flowers sampling unit. F. occidentalis adults showed aggregated distribution in greenhouse peppers. TPL coefficients were used to develop a fixed-precision sampling stop line. For control decision making, the pre-referred action thresholds were set at 3 and 18. With two action thresholds, N_max values were calculated at 97 and 1149, respectively. Using the Resampling Validation for Sampling Program (RVSP) and the results gained from the greenhouses, the simulated validation of our sampling method showed a reasonable level of precision.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.249-255
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• 2023

Korean melon (Cucumis melo L.) is grown mostly in Northeast Asia area, and as a fruit mainly produced in Korea, the yield per unit area continues to improve, but the cultivation method is limited to soil cultivation, so it is necessary to develop hydroponic cultivation technology for scale and labor-saving is needed. As the ratio of NO₃^- increased, the plant height, the leaf length, the leaf width, and the internode length became longer and larger. On the other hand, the SPAD value decreased. The lower the ratio of NO₃^-, the faster the female flower bloom, and there was no difference in fruit maturity between treatments. There was no difference in the shape of fruit according to the ratio of NO₃^-, and the hardness was higher as the ratio of NO₃^- was lower. The total yield from March to July was KM3 5,650 kg/10a and KM1 4,439 kg/10a, 27% higher in KM3 and, in particular, 36% higher in quantity from March to May, when Korean melon prices were high season. Therefore, it was judged that it would be appropriate to supply NO₃^- suitable for hydroponic cultivation of Korean melon, which was formalized in December and produced from spring, at the level of 6.5 to 10 me·L^-1.

• 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 $30^{\circ}$.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.37-81
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• 2015

AirAsia QZ8501 Jet departed from Juanda International Airport in, Surabaya, Indonesia at 05:35 on Dec. 28, 2014 and was scheduled to arrive at Changi International Airport in Singapore at 08:30 the same day. The aircraft, an Airbus A320-200 crashed into the Java Sea on Dec. 28, 2014 carrying 162 passengers and crew off the coast of Indonesia's second largest city Surabaya on its way to Singapore. Indonesia's AirAsia jet carrying 162 people lost contact with ground control on Dec. 28, 2014. The aircraft's debris was found about 66 miles from the plane's last detected position. The 155 passengers and seven crew members aboard Flight QZ 8501, which vanished from radar 42 minutes after having departed Indonesia's second largest city of Surabaya bound for Singapore early Dec. 28, 2014. AirAsia QZ8501 had on board 137 adult passengers, 17 children and one infant, along with two pilots and five crew members in the aircraft, a majority of them Indonesian nationals. On board Flight QZ8501 were 155 Indonesian, three South Koreans, and one person each from Singapore, Malaysia and the UK. The Malaysia Airlines Flight 370 departed from Kuala Lumpur International Airport on March 8, 2014 at 00:41 local time and was scheduled to land at Beijing's Capital International Airport at 06:30 local time. Malaysia Airlines also marketed as China Southern Airlines Flight 748 (CZ748) through a code-share agreement, was a scheduled international passenger flight that disappeared on 8 March 2014 en route from Kuala Lumpur International Airport to Beijing's Capital International Airport (a distance of 2,743 miles: 4,414 km). The aircraft, a Boeing 777-200ER, last made contact with air traffic control less than an hour after takeoff. Operated by Malaysia Airlines (MAS), the aircraft carried 12 crew members and 227 passengers from 15 nations. There were 227 passengers, including 153 Chinese and 38 Malaysians, according to records. Nearly two-thirds of the passengers on Flight 370 were from China. On April 5, 2014 what could be the wreckage of the ill-fated Malaysia Airlines was found. What appeared to be the remnants of flight MH370 have been spotted drifting in a remote section of the Indian Ocean. Compensation for loss of life is vastly different between US. passengers and non-U.S. passengers. "If the claim is brought in the US. court, it's of significantly more value than if it's brought into any other court." Some victims and survivors of the Indonesian and Malaysia airline's air crash case would like to sue the lawsuit to the United States court in order to receive a larger compensation package for damage caused by an accident that occurred in the sea of Java sea and the Indian ocean and rather than taking it to the Indonesian or Malaysian court. Though each victim and survivor of the Indonesian and Malaysia airline's air crash case will receive an unconditional 113,100 Unit of Account (SDR) as an amount of compensation for damage from Indonesia's AirAsia and Malaysia Airlines in accordance with Article 21, 1 (absolute, strict, no-fault liability system) of the 1999 Montreal Convention. But if Indonesia AirAsia airlines and Malaysia Airlines cannot prove as to the following two points without fault based on Article 21, 2 (presumed faulty system) of the 1999 Montreal Convention, AirAsia of Indonesiaand Malaysia Airlines will be burdened the unlimited liability to the each victim and survivor of the Indonesian and Malaysia airline's air crash case such as (1) such damage was not due to the negligence or other wrongful act or omission of the air carrier or its servants or agents, or (2) such damage was solely due to the negligence or other wrongful act or omission of a third party. In this researcher's view for the aforementioned reasons, and under the laws of China, Indonesia, Malaysia and Korea the Chinese, Indonesian, Malaysia and Korean, some victims and survivors of the crash of the two flights are entitled to receive possibly from more than 113,100 SDR to 5 million US$ from the two airlines or from the Aviation Insurance Company based on decision of the American court. It could also be argued that it is reasonable and necessary to revise the clause referring to bodily injury to a clause mentioning personal injury based on Article 17 of the 1999 Montreal Convention so as to be included the mental injury and condolence in the near future.

• Tuberculosis and Respiratory Diseases
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• v.65 no.3
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• pp.177-182
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• 2008

Background: Isoniazid (INH, H) is a key drug of the standard first-line regimen for the treatment of tuberculosis (TB), yet some reports have suggested that treatment efficacy was maintained even though INH was omitted from the treatment regimen. Methods: One hundred forty C57BL/6 mice were infected with the H37Rv strain of M. tuberculosis with using a Glas-Col aerosol generation device, and this resulted in depositing about 100 bacilli in the lung. Four weeks after infection, anti-TB treatment was initiated with varying regimens for 4-8 weeks; Group 1: no treatment (control), Group 2 (4HREZ): 4 weeks of INH, rifampicin (R), pyrazinamide (Z) and ethambutol (E), Group 3: 1HREZ/3REZ, Group 4: 4REZ, Group 5: 4HREZ/4HRE, Group 6: 1HREZ/3REZ/4RE, and Group 7: 4REZ/4RE. The lungs and spleens were harvested at several time points until 28 weeks after infection, and the colony-forming unit (CFU) counts were determined. Results: The CFU counts increased steadily after infection in the control group. In the 4-week treatment groups (Group 2-4), even though the culture was negative at treatment completion, the bacilli grew again at the 12-week and 20-week time points after completion of treatment. In the 8-week treatment groups (Groups 5-7), the bacilli did not grow in the lung at 4 weeks after treatment initiation and thereafter. In the spleens of Group 7 in which INH was omitted from the treatment regimen, the culture was negative at 4-weeks after treatment initiation and thereafter. However, in Groups 5 and 6 in which INH was taken continuously or intermittently, the bacilli grew in the spleen at some time points after completion of treatment. Conclusion: TThe exclusion of INH from the standard first-line regimen did not affect the treatment outcome in a murine model of TB in the early stage of disease. Further studies using a murine model of chronic TB are necessary to clarify the role of INH in the standard first-line regimen for treating TB.