• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.113-122
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• 1986

In order to promote mechanization of corn harvesting in Korea, this study was conducted to find out the effect of moisture content on compressive properties such as force, deformation, energy and modulus of stiffness to the bioyield and the rupture point for Korean corn kernel. In this study, the loading positions of corn were flat, edge, longitude and the moisture contents were about 13, 17, 21, 25% in wet basis. The compression test was carreied out with flat plate by use of dynamic straingage for three varieties of Korean corn under quasi-static force when the loading rate was 1.125mm/min. The results of this study are summarized as follows; 1. When the moisture content of corn ranged from 12.5 to 24.5 percent, at flat position, the bioyied force was in the range of 13.63-26.73 kg and the maximum compressive strength was in the range of 21.55-47.65kg. Their values were reached minimum at about 17% and maximum at about 21% moisture content. The bioyield force was in the range of 13.58-6.70kg at edge position and the maximum compressive strength which was 16.42 to 7.82kg at edge position was lower than that which was 18.55-9.05kg at longitudinal position. 2. Deformation of corn varied from 0.43 to 1.37 mm at bioyield point and from 0.70 to 2.66mm at rupture point between 12.5 to 24.5% moisture content. As the moisture content increased, deformation was increased. 3. The moduli of resilience and toughness of corn ranged from 2.60 to 8.57kg. mm and from 6.41 to 34.36kg. mm when the moisture content ranged from 12.5 to 24.5 percent, respectively. As the moisture content increased, the modulus of toughness was increased at edge position and decreased at longitudinal position. And their values were equal each other at 22-23% moisture content. 4. The modulus of stiffness was decreased with increase in the moisture content. Its values ranged from 32.07 to 5.86 kg/mm at edge position and from 42.12 to 18.68kg/mm at flat position, respectively. Also, the values of Suweon 19 were higher than those of Buyeo. 5. It was considered that the compressive properties of corn at flat position were more important on the design data for corn harvesting and processing machinery than those of edge or longitudinal position. Also, grinding energy would be minimized when a corn was processed between about 12.5 to 17% moisture content and corn damage would be reduced when a corn was handled between about 19 to 24% moisture content in wet basis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.19-27
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• 2017

The objective of this study was to determine the growth characteristics of cool (C1) and warm season grasses (C2) in pastures mixed with C1 and C2 at an altitude of 400 m in Jeju island to establishing pasture suitable for grazing horses and to evaluate the effect of pastures mixed with tall and short type grasses on the intake characteristics of horses. C1 used in this study was Kentucky bluegrass, redtop (short type grass) and tall type grasses were orchardgrass and tall fescue, respectively. Treatments of this study were consisted of four groups and the short type grass used in pastures mixed with C1 and C2 was mainly bermudagrass. Four treatment groups were follow as; Treatment 1 (bermudagrass + Kentucky bluegrass + redtop) 2) Treatment 2 (bermudagrass + tall fescue + orchardgrass) 3) Treatment 3 (Kentucky bluegrass + redtop) 4) Treatment 4 (tall fescue + orchardgrass). Bermudagrass was a little winter killing and inhibition of plant growth at an altitude of 400 m. Plant heights in pastures mixed with C1 and C2 were grown better than that in pastures mixed with C1. Especially, plant height in Treatment 4 was higher than other treatments. Dry matter yield was in the following order: Treatment 4> Treatment 3> Treatment 2> Treatment 1. Dry matter yield in pastures mixed with C1 increased as compared with pastures mixed with C1 and C2. Dry matter yield in Treatment 3 was higher than other treatments. In the first investigation regarding vegetation distribution, bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 11.7 and 13.3%, respectively. The growth of bermudagrass in winter was low due to the cold damage. However the growth of Kentucky bluegrass, redtop, tall fescue and orchardgrass was good. In the second investigation, bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 5.0 and 11.7%, respectively. Growth of forage in the second investigation was poor as compared to the first investigation. nutritive values(crude protein content, neutral detergent fiber content, acid detergent fiber content, digestibility) were good in pastures mixed with C1 Especially, nutritive values in pastures mixed with tall was higher than those of pastures mixed short grasses. P content among minerals in Treatment 1 was higher than other groups. However, the content of Ca, Mg and Mn were lower. The contents of Ca, K, Mg, Na, Cu, Zn and Fe in Treatment 2 were higher. However, the contents of K, Mg, Na, Cu, Zn and Fe in Treatment 3 were lower. Therefore, we suggest that cool season grasses with short grasses were sowed to establishing pasture suitable for grazing horses at an altitude of 400 m in Jeju island.

• Quality Improvement in Health Care
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• v.4 no.1
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• pp.50-63
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• 1997

Background : A pressure sore was defined as any skin lesion caused by unrelieved pressure and resulting in damage to underlying tissue. The health care institutions in the United States were reported the incident rate of pressure sores ranging from 6 to 14 %. Intensive Care Unit needed highest quality of care has been found over 40% incidence rate of pressure sore. Also, Annual expenditures for the care of pressure sores in patients in the United States have been estimated to be $7.5 billion; furthermore, 50 percent more nursing time is required to care for patients with pressure sore in comparison to the time needed to implement preventive measures against pressure sore formation. However, In Korea, there were little reliable reports, or researches, about incidence rates of pressure sore in health care institution including intensive care unit and about the integrated approach like CQI action team for risk assessment, prevention and treatment of pressure ulcers. Therefore, this study was to develop pressure sore risk assessment tool and the protocol for prevention of pressure sore formation through CQI action team activities, to monitor incident rate of pressure sore and the length of sore formation for patients at high risk, and to approximately estimate nursing time for sore dressing during research period as the effect of CQI action team. Method : CQI action team in intensive care unit, launched since early 1996, reviewed the literature for the standardized risk assessment tool, developed the pressure sore assessment tool based on the Braden Scale, tested its validity, compared on statistics including incidence rate of pressure sore for patients at high risk. Throughout these activities, CQI action team was developed the protocol, called as St. Marys hospital Intensive Care Unit Pressure Sore Protocol, shifted the emphasis from wound treatment to wound prevention. After applied the protocol to patients at high risk, the incident rate and the period of prevention against pressure development were tested with those for patients who received care before implementation of protocol by Chi-square and Kaplan-Meier Method of Survival Analysis. Result : The CQI action team found that these was significant difference of in incidence rate of pressure sores between patients at high risk (control group) who received care before implementation of protocol and those (experimental group) who received it after implementation of protocol (p<.05). 25% possibility of pressure sore formation was shown for the patients with 6th hospital day in ICU in control group. In experimental group, the patients with 10th hospital day had 10% possibility of pressure sore. Therefore, there was significant difference(p<.05) in survival rate between two groups. Also, nursing time for dressing on pressure sore in experimental group was decreased as much as 50% of it in control group. Conclusion : The collaborative team effort led to reduced incidence, increased the length of prevention against pressure sore, and declined nursing care times for sore dressing. However, there have had several suggestions for future study. The preventive care system for pressure sore should be applied to patients at moderate, or low risk throughout continuous CQI team activities based on Bed Sore Indicator Fact Sheet. Hospital-wide supports, such as incentives, would be offered to participants for keeping strong commitment to CQI team. Also, Quality Information System monitoring incidents and estimating cost of poor quality, like workload (full time equivalence) or financial loss, regularly in a hospital has to be developed first for supporting CQI team activities as well as empowering hospital-wide QI implementation. Being several limitations, this study would be one of the report cards for the CQI team activities in intensive care unit of an acute hospital and a trial of quality improvement of health care in Korea.

• Journal of Animal Science and Technology
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• v.55 no.4
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• pp.237-247
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• 2013

This study was to examine single or combined in vitro effects of environmental endocrine disruptors on boar sperm characteristics, oxidative stress damage in sperm and development of porcine IVF embryos. Addition of various concentration of NP (10, 20, $30{\mu}M$), DBP (10, 50, $100{\mu}M$) and BPA (1, 5 or $10{\mu}g/ml$) on boar sperm characteristics such as percentages of sperm motility, viability, membrane integrity and mitochondrial activity were dose-dependently decreased within 3, 6 or 9 hr incubation period (p<0.05). The overall detrimental effects increased with incubation time increasement. NP, DBP and BPA showed the detrimental effects on sperm membrane and mitochondria of energy production organelles affecting cell viability with the dependancy of dose and incubation time. In combination effects, NP ($10{\mu}M$) + DBP ($10{\mu}M$) significantly decreased boar general sperm characteristics for 3 or 6 hr incubation period compared with control (p<0.05). When both of NP and DBP concentrations (NP; $30{\mu}M$, DBP; $100{\mu}M$) increase, the detrimental effects on sperm characteristics were larger than those of low concentration combination (p<0.05). The inhibitory effects of NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$) on sperm characteristics were larger than those of NP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) (p<0.05). DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) decreased sperm characteristics compared with the low concentration combination (DBP $10{\mu}M$ + BPA $1{\mu}g/ml$, p<0.05). This result indicates the detrimental effects of both chemicals on sperm characteristics were dose dependent. Addition of NP ($30{\mu}M$) + DBP ($100{\mu}M$), NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$), DBP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) or DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) significantly increased lipid peroxidation for 3 or 6 hr incubation period (p<0.05) compared with no addition control. NP (${\geq}20{\mu}M$) decreased the percentages of IVF embryo development from morulae and blastocyst stages (p<0.05) and its detrimental effects were dose-dependant. BPA 0, 1, 5 or $10{\mu}g/ml$ decreased significantly and dose-dependently the percentage of morulae plus and blastocysts (p<0.05). Combinations of DBP ($100{\mu}M$) plus NP ($30{\mu}M$) and DBP ($100{\mu}M$) plus BPA ($10{\mu}g/ml$) did not affect on morulae and blastocyst development, but NP ($30{\mu}M$) plus BPA ($10{\mu}g/ml$) has significant detrimental effect on embryo development at these stages (p<0.05). These overall results indicate that the partial detrimental effects on boar sperm characteristics and embryo development by NP, DBP, BPA or the combination of these chemicals might be due to the increasement of lipid peroxidation and free radical formation in the cell and there were no specific interaction effects on boar sperm and embryo degeneration among the combined treatments.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.292-292
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• 2016

Transition metal dichalcogenides (TMDs) with a two-dimensional layered structure have been considered highly promising materials for next-generation flexible, wearable, stretchable and transparent devices due to their unique physical, electrical and optical properties. Recent studies on TMD devices have focused on developing a suitable doping technique because precise control of the threshold voltage ($V_{TH}$) and the number of tightly-bound trions are required to achieve high performance electronic and optoelectronic devices, respectively. In particular, it is critical to develop an ultra-low level doping technique for the proper design and optimization of TMD-based devices because high level doping (about $10^{12}cm^{-2}$) causes TMD to act as a near-metallic layer. However, it is difficult to apply an ion implantation technique to TMD materials due to crystal damage that occurs during the implantation process. Although safe doping techniques have recently been developed, most of the previous TMD doping techniques presented very high doping levels of ${\sim}10^{12}cm^{-2}$. Recently, low-level n- and p-doping of TMD materials was achieved using cesium carbonate ($Cs_2CO_3$), octadecyltrichlorosilane (OTS), and M-DNA, but further studies are needed to reduce the doping level down to an intrinsic level. Here, we propose a novel DNA-based doping method on $MoS_2$ and $WSe_2$ films, which enables ultra-low n- and p-doping control and allows for proper adjustments in device performance. This is achieved by selecting and/or combining different types of divalent metal and trivalent lanthanide (Ln) ions on DNA nanostructures. The available n-doping range (${\Delta}n$) on the $MoS_2$ by Ln-DNA (DNA functionalized by trivalent Ln ions) is between $6{\times}10^9cm^{-2}$ and $2.6{\times}10^{10}cm^{-2}$, which is even lower than that provided by pristine DNA (${\sim}6.4{\times}10^{10}cm^{-2}$). The p-doping change (${\Delta}p$) on $WSe_2$ by Ln-DNA is adjusted between $-1.0{\times}10^{10}cm^{-2}$ and $-2.4{\times}10^{10}cm^{-2}$. In the case of Co-DNA (DNA functionalized by both divalent metal and trivalent Ln ions) doping where $Eu^{3+}$ or $Gd^{3+}$ ions were incorporated, a light p-doping phenomenon is observed on $MoS_2$ and $WSe_2$ (respectively, negative ${\Delta}n$ below $-9{\times}10^9cm^{-2}$ and positive ${\Delta}p$ above $1.4{\times}10^{10}cm^{-2}$) because the added $Cu^{2+}$ ions probably reduce the strength of negative charges in Ln-DNA. However, a light n-doping phenomenon (positive ${\Delta}n$ above $10^{10}cm^{-2}$ and negative ${\Delta}p$ below $-1.1{\times}10^{10}cm^{-2}$) occurs in the TMD devices doped by Co-DNA with $Tb^{3+}$ or $Er^{3+}$ ions. A significant (factor of ~5) increase in field-effect mobility is also observed on the $MoS_2$ and $WSe_2$ devices, which are, respectively, doped by $Tb^{3+}$-based Co-DNA (n-doping) and $Gd^{3+}$-based Co-DNA (p-doping), due to the reduction of effective electron and hole barrier heights after the doping. In terms of optoelectronic device performance (photoresponsivity and detectivity), the $Tb^{3+}$ or $Er^{3+}$-Co-DNA (n-doping) and the $Eu^{3+}$ or $Gd^{3+}$-Co-DNA (p-doping) improve the $MoS_2$ and $WSe_2$ photodetectors, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.483-491
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• 2014

Double cropping system including paddy field soybean is widely adopted nationwide, due to rise in market price and its higher income than paddy field rice. Sowing date of soybean as a second crop is being delayed depending on first crop's growth period and harvesting time. Due to the increased temperature in October and delayed first frost date, soybean could be harvested without frost damage even in late-plating. Therefore, selection of soybean cultivar which is appropriate for this environment is very important. The effect of sowing date and genotype of soybean on growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with ten cultivars developed for soy-pate production, to figure out plant development and yield pattern in delayed planting. As planting date is delayed, plant height and pod number was decreased and this pattern was more clearly detected in mid-late maturity cultivars. Hundred-seed weight did not show significant changes even in late planting, due to compensations between yield components. Yield reduction of July 20 in contrast to that of June 20 showed that Nampung (9.6%) showed the least yield decline. Maximum yield was achieved from Daepung, Taekwang, and Uram among other soybean cultivars in late planting. Shortening of growth period was strongly detected in reproductive stage while length of vegetative stage was regularly maintained in both early and mid-late maturity cultivars.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.457-464
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• 2005

The purpose of our study was to investigate whether the intrapulpal temperature during cavity preparation of enamel or dentin with Er:YAG laser still remained in range of safety for dental pulp protection when combined with appropriate water flow rate. The effect of different pulse repetition rates at the same pulse energy during ablation was evaluated as well. Caries-free, restoration-free extracted human molar teeth were prepared for the specimen and divided two experimental groups of enamel and dentin. Each group comprised 5 specimens and each of tooth specimens were embedded into a resin block each and measuring probe was placed on the irradiated pulpal walls. For experiments of dentin ablation, enamel layers were prepared to produce dentin specimen with a same dentin thickness of 2 mm. A pulse energy of Er:YAG laser was set to 300 mJ and three different pulse repetition rates of 20 Hz, 15 Hz and 10 Hz were employed. Laser beam was delivered with 3 seconds and less per application over enamel and dentin surfaces constant sized by $3\;mm{\times}2\;mm$ and water spray added during irradiation was a rate of 1.6 ml/min. Temperature change induced by Er:YAG laser irradiation was monitored and recorded While enamel was ablated, there was no significant difference of temperature related to pulse repetition rates(p=0.358) and temperature change at any pulse repetition rate was negligible. Significant statistical difference in temperature changes during cavity preparation in dentin existed among three different pulse groups(p=0.001). While temperature rise was noticeable when the dentinal wall was perforated, actual change of temperature due to Er:YAG laser irradiation was not enough to compromise safety of dental pulp when irradiation was conjugated with appropriate water spray. Conclusively, it can be said that cavity preparation on enamel or dentin with an Er:YAG laser is performed safely without pulp damage if appropriate volume of water is sprayed properly over the irradiated site.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.101-108
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• 2005

Because the stone cultural properties located outdoors, they have been altered and deteriorated in external appearance due to environmental factors such as acid rain, extreme change in temperature, and salts. Damage to stone cultural properties is accelerated particularly due to recent industrial development and environmental pollution. An experimental study was conducted to evaluate the effect of environmental contaminants on the weathering of granite. And as part of the developing of conservation method, $TiO_2$ catalyst was prepared and tested. When fresh granite was dipped into the salt and acid solutions, dissolution rate of eight minerals (Si, Mg, Ca, Na, K, Fe, Mn, Al) are abruptly increased at initial stage of reaction and then increased steadily until 100 cycles. After salt and acid solution experiments, the mineral compositions of the granite surface were lower then that of the fresh granite and density of the weathered granite was steadily decreased from $2.60\;g/cm^3$ to $2.56\;g/cm^3$, but Poissions ratio and absorption ratio were slightly increased. It was expected at stone cultural assets could be weathered by salts and acid rain. In the case of $TiO_2$ was coated to the granite, the dissolution rate of minerals and absorption ratio of $TiO_2$ coated granite were decreased. Therefore, the $TiO_2$ coating method tested in this study considered to be a viable method to assist in the conservation of stone cultural properties from environmental contaminants.

• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.165-174
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• 1999

Boar semen can be frozen successfully. However, there is a large variability in the extent of damage boar semen samples experiences during cryopreservation. This experiment was undertaken to find out factors that affect a post-thaw viability of boar spermatozoa. For this purpose, cryodiluents(BF5, LEY, Soejima and M-Soejima), cryoprotectants(glycerol. ethylene glycol, and propylene glycol), pre-freezing method(dryice-pellet, dryice-straw and L$N_2$vapour-st-raw) and total time required for freezing(2. 5, and 7 h) were compared as a factors. To investigate quality of semen during freezing process, motility(%), normal apical ridges(%, NAR), and proportion of living sperm(%) by flow cytometic analysis were assessed after collection, cooled, pre-frozen and post-thawing. Post-thaw motility of semen diluted with M-Soejima was 52.0%, respectively. When heparin, caffeine or heparin＋caffeine was added to 2nd cryodiluent of M-Soejima during freezing process, the highest motility after thawing was shown at the addition of caffeine (2mM), with 61.7$\pm$2.9% of motility. M-Soejima with heparin or caffeine was significantly higher than that of controI(p＜0.05). The result using glycerol(Gly), ethylene glycol(EG), propylene glycol(PG), and their mixture (Gly＋EG and Gly＋PG) as cryoprotectants, the highest motility was shown at the mixture treatment with Gly plus PG. However, the highest proportion of live spermatozoa was shown at Gly＋EG, there was no significantly difference among treatments(p＞0.05). When semen was pre-frozen with three manners(dryice-pellet, dryice-straw, and L$N_2$ vapor-straw), motility(%) of post-thaw spermatozoa was the highest in the L$N_2$ vapor-straw pre-freezing method of M-Soejima cryodiluent with 57.5% of motility, For a simple, economical and timesaving approach to freezing boar semen, total time required for freezing were 2, 5, and 7 hours, post-thaw motility were 43.8, 45.0 and 38.8%, NAR were 19.5, 22.7 and 28.5%, and viability were 20.8, 19.9 and 22.1%, respectively. This data suggests that boar semen diluted with M-Soejima cryodiluent contained caffeine, using mixture of glycerol and propylene glycol or ethylene glycol as cryoprotectants, frozen with 2 hours, can be taken better motility, NAR, and proportion of live spermatozoa.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.139-144
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• 1969

1. In order to obtain useful mutants such as early maturity, resistance to lodging, high protein and oil content, and capability of high yield, dormant seeds of two soybean varieties, Jang Dan Baik Mok and Clark, were treated with ${\gamma}$-ray, Ethyl Methane Sulfonate(EMS), Ethylene Imine(EI)and combinations of ${\gamma}$-ray and EMS or EI. 2. The germination rate and survival rate in a variety Jang Dan Baik Mok were significantly decreased with ${\gamma}$-ray treatment while it was not the same in the Clark variety. A significant decrease for seedling height measured at 14 and 21 days after sowing was found with the increase of ${\gamma}$-ray dose in both varieties. 3. Germination rates in both varieties were significantly decreased as EI concentration increases, particularly severe damage in germination was observed at 0.008 Mo. concentration. Germination rate damages were found with EMS concentration increases in the variety Jang Dan Baik Mok while no regular responses in seedling height were observed in the variety Clark. 4. Germination rate was significantly lowered with the combined treatment of EMS and ${\gamma}$-ray 24KR than that of EMS alone. In the treatments of ${\gamma}$-ray with three levels of EI concentration, the combined treatments except 24KR+EI 0.002 Mol. resulted in better germination than of EI alone. In both varieties, significant reduction in seedling height was observed in the combined treatments of ${\gamma}$-ray with various concentrations of EMS, whereas stimulation effect on seedling height was found with treatment of ${\gamma}$-ray EI +0.08Mol. 5. Germination rate, survival rate, and plant height as criteria of radio sensitivity, variety Jang Dan Baik Mok is moze sensitive to ${\gamma}$-ray, EMS, and EI than the variety Clark, and the varietal difference in responsibility to mutagen may be due to the genetic-constitution of the varieties.