• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.395-403
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• 2013

Plant factory has drawn attention in many countries in the world due to capability of environmental control not only for better yield and quality, but also for increase in functional and medicinal components of the products. In this paper, an experimental plant factory was constructed for various tests under different environmental conditions, and the operations were evaluated. A production room was constructed with adiabatic materials with dimensions of $6,900{\times}3,000{\times}2,500$ mm ($L{\times}W{\times}H$). Four sets of $2,890{\times}600{\times}2,320$ mm ($L{\times}W{\times}H$) production frame unit, each with 9 light-installed beds and an aeroponic fertigation system, resulting in 36 beds, were prepared. Accuracy and response were evaluated for each environmental control component with and without crops. Air temperature, humidity, $CO_2$ concentration, light intensity, frequency, and duty ratio, fertigation rate and scheduling were controllable from a main control computer through wireless communication devices. When the plant factory was operated without crop condition, the response times were 8 minutes for change in temperature from 20 to $15^{\circ}C$ and 20 minutes from 15 to $20^{\circ}C$; 7 minutes for change in humidity from 40 to 65%; and 4 minutes for change in $CO_2$ concentration from 450 to 1000 ppm. When operated for 24 hours with crop cultivation; average, maximum, and minimum values of temperatures were 20.06, 20.8, and $18.8^{\circ}C$; humidity were 66.72, 69.37, and 63.73%; $CO_2$ concentrations were 1017, 1168, and 911 ppm, respectively. Photosynthetic Photon Flux Density was increased as the distance from the light source decreased, but variability was greater at shorter distances. Results of the study would provide useful information for efficient application of the plant factory and to investigate the optimum environment for crop growth through various experiments.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.435-443
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• 2015

Offshore structure may be considerably vulnerable to fatigue failure while initial flaw propagates under cyclic loading, so crack propagation analysis/fracture/yield assessments about initial flaw detected by NDT are necessarily required. In this paper, case studies have been conducted by flaw assessment program using engineering criticality analysis (ECA) approach. Variables such as flaw geometry, flaw size, structure geometry, dynamic stress, static stress, toughness, crack growth rate, stress concentration factor (SCF) affected by weld are considered as analysis conditions. As a result, the safety of structure was examined during fatigue loading life. Also, critical initial flaw size was calculated by sensitivity module in the developed program. The flaw assessments analysis using ECA approach can be very useful in offshore industries owing to the increasing demand on the engineering criticality analysis of potential initial flaws.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.103-107
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• 2003

Phosphorus (P) is a macronutrient playing important roles in many plant processes. Significant interest has been devoted to search and utilize genotypic variations in P use efficiency in rice but with little effort to understand its physiological and biochemical bases. In this study, we examined responses to P deprivation of some primary and secondary traits in 3-week-old seedlings of the three genotypes, Sobi-byeo (japonica), Dasan-byeo (japonica $\times$ indica) and Palawan (indica). In general, percent weight due to root was increased up to 26%, but amounts of root protein and proteins secreted from roots were decreased by 11 to 19% and 31 to 51 %, respectively, by 3 to 21 days of P deprivation in the three genotypes. Interestingly, however, responses of Palawan to short-term P deprivation were contrasting to those of Dasan-byeo and Sobi-byeo in seedling weight and contents of shoot protein, chlorophyll and anthocyanin. Seedling weight was not decreased, but shoot protein content was decreased in P-deprived seedlings of Palawan. Contents of chlorophyll in leaves and anthocynin in roots were increased in Dasan-byeo and Sobi-byeo, but decreased in Palawan. The results suggest that responses of protein and pigment synthesis to P deficiency are different in modem and traditional varieties and the difference may at least in part be due to the selection for high yield under highly fertilized conditions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.108-108
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• 2017

The objective of this study was to know prospect and present state of new variety breeding of Forage and Grassland in South Korea. The industry of forage in Korea is going up to expend through utilization of good quality forage, Italian ryegrass, forage corn and oat rather than rice straw. Especially, since 2007, Italian ryegrass(IRG) had been very important major winter forage crop in South Korea and developed 13 varieties including very early maturity variety (three varieties), early maturity variety (three varieties), medium maturity variety (one variety) and late maturity variety (six varieties). But the disadvantage of Italian ryegrass was weak winter hardness and drought but has good advantage of forage nutritive value, high-yielding and high sugar content, and like livestock as like hanwoo, dairy cattle, goat so on. The Ko-variety (Korea developed variety) of Italian ryegrass has high cold-tolerant and adaptability more than any other country developed variety, and expend to cultivation area from southern area (below Daejeon) to middle-northern area (upper Han river). Although the cultivation area of Italian ryegrass of South Korea was 21,700 ha in 2007, right now, that of Italian ryegrass is about 123,600ha due to expend cultivation area and know famer to good forage crop and have a various maturity varieties (very early, early, medium, late) according to local situation (before-crop harvesting stage or double cropping system). The seed market of Italian ryegrass in South Korea becoming extended to around 100 million Korean won and seed export get nearer to foreign country. We are going to develop of new variety for stress tolerant and high yield and quality forage variety, good adaptability to the Korean environmental conditions including reclaimed area, make self-sufficiency system for forage seed (Italian ryegrass), export our seed to foreign countries.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.60-60
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• 2017

It is important to measure the gas exchange activity of the crops in canopy scale to understand the process of biomass production and yield formation. Thermal imaging of the canopy surface temperature is a powerful tool to detect the gas exchange activity of the crop canopy. The simultaneous measurement of the canopy temperature and the meteorological data enables us to calculate the canopy diffusive conductance ($g_c$) based on the heat flux model (Monteith et al. 1973, Horie et al. 2006). It is, however, difficult to realize the long-term and continuous monitoring of $g_c$ due to the occurrence of the calculation error caused by the fluctuation of the environmental condition. This is partly because the model assumption is too simple to describe the meteorological and aerodynamic conditions of the crop canopy in the field condition. Here we report the novel method of the direct measurement of the aerodynamic resistance ($r_a$) of the crop canopy, which enables us the stable and continuous measurement of the gas exchange capacity of the crop plants. The modified heat balance model shows the improved performance to quantify $g_c$ under the fluctuating meteorological condition in the field. The relationship between $g_c$ and biomass production of rice and soybean varieties is also discussed in the presentation.

• The Journal of Engineering Geology
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• v.14 no.4 s.41
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• pp.391-400
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• 2004

Excess pumping on the river bank filtration well causes the over drawdown in the protected area of bank, which may make many problems such as soil water contents, Pumping head in the irrigated land, and it needs more irrigation and development of the deeper irrigating well. In this study the installation of the artificial recharging well was suggested to reduce the excess draw down in the protected land. Artificial recharging wells were applied at the bank filtration site of Changwon city by using Visual-MODFLDW. The optimized conditions are calculated that the recharging well is located about loom apart from the pumping well, and the recharging rate is $5\%$ of the pumping yield.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.353-363
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• 2012

The geology of Ulleung-Do is dominated by volcanic rocks with low strength and trachytic rocks with high strength but containing vertical joints that yield easily. Consequently, rockfalls along roadcuts are a major geological hazard, with the potential to affect the ring road of Ulleung-Do. In this study, we performed three types of rockfall hazard-risk assessment on the 3-km-long section of the ring road expected to have the highest possibility of rockfall. We used a rockfall ranking sheet in a roadside landslide hazard map, the Slope Stability Inspection Manual for National Highways (Japan), and a rockfall hazard rating system for inspection from the Japan Highway Public Corporation. We also employed the evaluation criteria of 'RHRS' developed by the Federal Highway Administration (FHA). An analysis of roadcuts at 27 sites with regard to geographic and geological conditions resulted in the identification of three classes of rockfall hazard (high, medium, and low). Of note, over 74% of slopes were assessed as high- and medium-class. Finally, a rockfall hazard map of the northeast region of Ulleung-Do was produced based on the evaluation results.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.104-115
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• 1992

The present study was conducted to compare the relative efficiency of four different breeding methods in tobacco varietal development. A single Fl hybrid plant from cross of two flue-cured cultivars of Nicotiana tabacum L Bright Yellow 4(BY4) and NC95, was selfed. F2population above cross was screened for resistance against bacterial wilt caused by Pseudommonas solanacearum E.F.Smith under the naturally infested field conditions, and the 30 lines were developed from F2 individual plant by anther culture (ADH), maternal method utilizing Nicotiana afpicana (MDH), single- seed descent(SSD) and Bulk breeding method, respectively. All characters except content of total alkaloids of ADH and MDH which wore bred by haploid methods reduced more than that of lines bred by conventional methods(SSD & Bulk) : however, the yields were 8% lower than other lines. The total alkaloid content of ADH was higher than that of MDH, and yield was reduced about 4n even though the number of leaf was identical with the MDH. All other characters of ADH were also reduced significantly. In the lines bred by conventional methods, population developed by SSD showed significantly wider leaf width, shorter plant height, later days to flower, and lower in percent reducing sugar than those by Bulk. The populations derived from haploid method showed greater phenotypic variance and wider range of variation than conventionally developed ones. The results obtained indicate that selection will provide a significantly greater genetic gain for leaf number and leaf length in the ADU and MDH populations, and for plant height and days to flower in the SSD and Bulk populations.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.63-63
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• 2010

The pre-heat free consumables for GMAW, SAW and FCAW processes that matches the Cu-bearing PFS-700 steel which has yield strength over 700MPa were developed and evaluated to see the suitability in military such as submarine and battle ship. Explosion bulge test in underwater was developed and applied to see the reliability of welded structure. All welding was conducted without pre-heat before welding, the interpass temperature was below $150^{\circ}C$ for all welding conditions. Tensile strength for the weld metal in GMAW, SAW and FCAW process is 887MPa, 875MPa and 813MPa, respectively, these values are similar to the base metal of PFS-700 steel of 838MPa. EBT results in GMAW, SAW and FCAW show 14.0%, 14.02% and 15.9% reduction of thickness without generation of crack, respectively and stand-off distance was set up properly to have over 14.0% reduction of thickness. Through EBT results, the developed new consumables are applicable to the weapon systems such as submarine and battle ship.

• Journal of fish pathology
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• v.11 no.2
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• pp.89-96
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• 1998

Marine birnavirus (MABV) has wide host range in marine organisms. To clarify various infection properties of MABV in different host species, in vitro study was performed by subculture for 10 passages in several fish cell lines. In CHSE-214, RTG-2 and RSBK-2 cells, the virus produced high yield of virus. Typical CPE with high protein expression was observed in these cells. On the contrary, the virus grown in EPC, FHM and BF-2 cells exhibited no CPE appearance although virus protein was detected. In EPC and FHM cells, the virus titer increased in later passages. The plaque size was distinctly bigger in CHSE-214, RTG-2 and RSBK-2 cells than in other cell lines. The nucleotide sequence of VP2/NS junction region on genome segment A exhibited one specific nucleotide change at 195. The different infection properties in several cell types performed in the present work might reflect in vivo MABV infection in various host species occurring in natural conditions.