• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.150-156
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• 2000

In this paper, the human error contributions to the system unavailability are calculated and compared to the mechanical failure contributions. The system unavailability is a probability that a system is in the failed state at time t, given that it was the normal state at time zero. It is a function of human errors committed during maintenance and tests, component failure rates, surveillance test intervals, and allowed outage time. The THERP (Technique for Human Error Rate Prediction), generally called "HRA handbook", is used here for evaluating human error rates. This method treats the operator as one of the system components, and human reliability is assessed in the same manner as that of components. Based on the calculation results, the human error contribution to the system unavailability is shown to be more important than the mechanical failure contribution in the example system. It is also demonstrated that this method is very flexible in that it can be applied to any hazardous facilities, such as gas valve stations and chemical process plants.ss plants.

• Applied Science and Convergence Technology
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• v.25 no.6
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• pp.145-148
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• 2016

This paper, Al-doped ZnO(AZO) thin films for application as transparent conducting oxide films were deposited on the Corning glass substrate by using RF magnetron sputtering system. The effects of various Argon gas flow rates on optical and electrical characteristics of AZO films were investigate sputtering method. The Carrier Concentration is enhanced as Ar gas rate increases, and also the oxygen vacancy concentration. The figure of merit obtained in this study means that AZO films which deposited Ar gas rate of 75 sccm have the highest Carrier concentration and Hall mobility, which have the highest photoelectrical performance that it could be used as transparent electrodes.

• Asian Journal of Turfgrass Science
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• v.3 no.1
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• pp.39-52
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• 1989

Native Kerean lawngrass (Zeysia japonica steud.) and Manilagrass ( Zeysia matrella Merr.) are frequently used as sport turf and lawn in Kerea and ether Asian countries because of its excellent summer qualities and superior winter-hardiness compared to ether warm-season turfgrass . The objective of this study was to investigate the effect of the plant growth retardants ( PGR ) en the inhibition (d the growth of the two Kerean native turfgrasses. Kerean lawngrass and Manilagrass were treated with [2 RS , 3 RS] -1- [4- chlorophenyl ] -4, 4-dimethyl -2- [1 H -1, 2, 4- tiazol -1- y] pentan -3- ol ( PP -333) at 93 and 930 gha -j ; 5-[4- chlorphenyl ]-3, 4, 5, 9, 10- peiitaaza - tetracyclo [5, 4, 1, 0 2 6 . o ~'~I -3, 9- diene ( BAS -106) at 16 and 160 gha ; [ E I-] - cyclohexyl -4, 4- dimethyl -2- [1, 2, 4- triazol -1- yl ]-1-pentene - 3- ol ( NTN -821) at 56 and 560 gha ', and 4- chloro -2- [$\alpha$- hydrozybenzy I isonicotin anilide ( CGR -811) at 92 gha in pot study . All PGR treatments were effective in reducing the plant height, with the exception of BAS -106 at 16 gha for Korean lawngrass ; however , all increased quality to some degree , with the exception of PP -333 at 93 gha . The low PGR rates significantly increased Korean lawngrass height during late jtily aitd mid-August . On the other hand , BAS -106 significantly increased Manilagrass height {rom 24 Septeml)er onwards . All PGR treatments haol higher turfgrass quality than untreatments , and also the high rates of PGIt treatments were more effective in increasing quality than the low rates observed on 8 October . Meanwhile , Manilagrass quality was increased to some extent than Korean lawegrass . PP - 333 was significantly effective in reducing clipping yield and the same results were found with the application of NTN -821 at 560 gha -l for both Korean lawngrass and Manilagrass , BAS -106 at 160 gha for Korean lawegrass , and CGR -811 at 92 gha for Manilagrass . The high PGR rates had higher turfgrass shoot weight observed on 8 October than the low rates , and there were little increases obtained with the low rates of PP -333 for Korean lawngrass and BAS - 1 06 for Manilagrass . Effeets on stolon growth varied between growth retardants , and between retardant treatments ; the high rates of PGR as well as the low rate of NTN -821 elongated stolon of Korean lawngrass and manoilagrass . However , PP -333 at 93 gha and BAS -106 at 16 gha - shortened stolons of Korean lawugrass , resulting in inhibition or little difference of stolon dry weight . NTN -821 at 560 gha and CGR -811 had no positive effect on the stolon length of Manilagrass . 101) -333 and the low rate of BAS -106 and NTN -821 decreased root weight of Korean lawng - rass All PGR rates had negative effect on the root weight of Manilagrass with the exception of BAS -106 CR -811 and the high rate of NTN -821 which made no difference in root weight between retarolant treatments and the control .

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.104-109
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• 2013

The paper will outline how hazard identification and risk evaluation can effectively be performed to obtain Tolerable Hazard Rates (THR). As a target group manufacturers are addressed, who face the situation, that for a generic application THRs are needed for compliance with EN 50129 [1]. Focusing on functional hazards this paper shows a possible hazard log and the relevant analysis methods. The terms safety barrier and barrier function will be introduced and used instead of the term "safety function". As functional hazards and barrier functions depend on each other, emphasis will be put on a comprehensive and detailed definition of barrier functions and the usage of function lists. By using detailed and complete hazard and barrier function definitions THRs can be obtained while at the same time the approach becomes clear how the hazard rates (HR) will be established.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.173-177
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• 2002

THERP (Technique for Human Error Rate Prediction) methodology has been widely used for probabilistic safety assessments. The NUREG report involving this methodology is also called the HRA handbook. The THERP assumes that all actions involved in implementing a task are considered as components. In this paper human error rates associated with maintenance are evaluated by the THERP methodology. A gas governor system is used as an example which is also a risky system like nuclear power plants. It is also demonstrated that this approach is flexible in that it can be applied to any operator actions related to test and maintenance.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.318-324
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• 2017

Lime bordeaux mixture (LBM) and lime sulfur mixture (LSM) are representative environmental friendly organic materials for prevention of insect pests in South Korea. Recently, those have been widely used as an alternative for chemical pesticides in eco-friendly farms. However, South Korea has not established even recommendation of LBM and LSM considering the stability of heavy metals in soil. The aim of this study was to evaluate the accumulation of hazardous heavy metals in soil and plant with long-term application of LBM and LSM. Firstly, we investigated the amount of LBM and LSM used per year in several eco-friendly farms to determine a standard application rate of both materials. The pepper plant was grown on the pot in greenhouse for 14 weeks. Both materials were applied at 0, 1, 3, and 9 times of standard application rates (2.56 and $1.28L\;ha^{-1}$ of LBM and LSM per year, respectively). Dry matter yield of pepper and heavy metals (As, Cd, Cu, Hg, Ni, Pb, and Zn) concentration in soil and pepper plant were measured after 14 weeks. Yield of pepper plant did not significantly chang with up to application rate of 1 times, thereafter it markedly decreased with more than 3 times. With increasing LBM and LSM application, the concentration of Cu and Zn in soil significantly increased. Especially, Zn concentration in pepper significantly increased with increasing application rates of both materials. This might resulted in significant decrease in dry matter yield of pepper. The concentrations of those heavy metals in soil did not exceed safety levels ($150mg\;kg^{-1}$ for Cu and $300mg\;kg^{-1}$ for Zn) established by the Korean Soil Environmental Conservation Act as well as concentration of heavy metals in pepper plant by Korean Ministry of Food and Drug Safety. However, particular attention should be paid for heavy metal safety and crop productivity when using LBM and LSM in the organic farm.

• Korean Journal of Agricultural Science
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• v.51 no.3
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• pp.271-281
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• 2024

The application of biochar to soil for sustainable agriculture has been considered to have a positive impact on soil fertility and crop productivity. In this study, biochar derived from rice husk and chicken manure was applied to the soil at rates of 1% and 3% by weight, respectively, for lettuce cultivation experiments. The results indicated that both rice husk biochar and chicken manure biochar were effective in improving soil fertility through soil pH correction and increased nutrient content. The nitrogen content and pH of the biochar increased the available nitrogen and phosphate in the soil, creating a soil environment conducive to the growth enhancement of lettuce. In particular, after the application of 3% chicken manure biochar, the soil exhibited the highest levels of available nitrogen and phosphate at 87.42 mg·kg^-1 and 69.07 mg·kg^-1, respectively. Plant fresh weight increased with rising biochar amount, with the 3% chicken manure biochar treatment (228.25 g·plant^-1 fresh weight [FW]) exhibiting superior fresh weight compared to 3% rice husk biochar treatment (120.88 g·plant^-1 FW). The nutrient content in lettuce, except for K₂O, was higher in the chicken manure biochar treatment compared to the same dosage of rice husk biochar. Therefore, for enhancing lettuce productivity and soil fertility, chicken manure biochar appears to be more effective than rice husk biochar, and increasing the application rate up to 3% showed improvement effects without adverse impacts. However, excessive application of chicken manure biochar may lead to an increase in soil pH and electrical conductivity (EC) beyond the optimal range, requiring further assessment of application rates.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.119-124
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• 2015

In this study, we sought to evaluate the growth characteristics and seed productivities of domestic tall fescue that were cultivated with differing combinations of drill widths and nitrogen-application rates in early spring; the examination was conducted at the National Institute of Animal Science, RDA, from 2013 to 2014. The main plots were three widths of 15 cm, 30 cm, and 45 cm, and the subplots were subject to nitrogen-application rates in early spring of 45 kg/ha, 90 kg/ha, 135 kg/ha, and 180 kg/ha. The growth and development characteristics did not vary by treatment in terms of drill width and early-spring nitrogen application. Tall fescue Purumi showed a stable seed productivity of two tons or greater when the drill width was set at 15 cm and 90 kg/ha of nitrogen was applied in early spring. The narrower the drill width, the greater the numbers of both the ears and seeds, while the length of the ear was longer when the drill width was wider. Regarding the influence of the drill width and early-spring nitrogen application on the productivity of seed-producing straw, the dry matter productivity was higher when the drill width was narrower; however, no particular trend was observed with respect to different amounts of fertilizer. The average production amount of the first round of straw after seed gathering was 6,920 kg/ha. The second round produced an average 8,134 kg/ha of dry matter.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.87-92
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• 2017

Objective of this experiment was to evaluate the effect on pepper growth to application of biochar pellet in case of development of soil carbon sequestration technology. The treatments consisted of control as a general agricultural practice method, pellet (100% pig compost), biochar pellets with mixture ratio of pig compost (9:1, 8:2, 6:4, 4:6, 2:8) for comparison of total carbon contents, $NH_4-N$ concentrations, and total biomass in the pots applied with biochar pellets after pepper harvesting. The application rates of biochar pellet was 8.8 g/pot regardless of their mixed rates based on recommended amount of application (440 kg/10a) for pepper cultivation. For the experimental results, Total carbon contents in the treatments were low from 1.8 to 2.6 fold as compared to the control. $NH_4-N$ concentrations were not significantly different among the treatment plots as compared to the control, but $NO_3-N$ was not detected in the all treatment plots. However, total biomass was not only significantly different between the control and 2:8 (biochar : pig compost) biochar pellet application plot even if the other treatments were low. Therefore, this biochar pellet application might be further modified for soil carbon sequestration in agricultural farming practices.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.107-112
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• 1974

In order to establish a rational application method of potash to paddy rice(Oryza sativa L. Jinheung, a Japonica variety) field and pot experiments on split application of two rates (6kg and 12kg $K_2O$ per 10a) of potash at a certain critical growing stage have conducted in 1973 and the results were as follows: 1. At the treatment where a rate of 6kg $K_2O$ per 10a(lower dose) of potash was supplied in two split doses, a half at transplanting time and the other half at young panicle formation stage, the yield of paddy rice appeatred to be low due to less number of panicles per hill. (Field experiment) 2. The treatment where potash supply ceased at transplanting time or at effective tillering stage but supplied at the other two stages (including panicle initiation stage) have failed to increase K content in the flag leaf and have shown low maturity and low thousand grain weight, which resulted in low paddy rice yield. (pot experiment) 3. From above two facts, it is concluded that the application of potash at transplanting time is an important practice for the high yielding of paddy rice. 4. The application of lime seemed to stimulate later growth of paddy depressing the unnecessary increase of poor miserable tillers in early stages of growth.