• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.10-16
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• 2018

Lindera erythrocarpa is a less utilized species in Korea although that it has straight stem and it grows up to 40 cm in diameter. A proper kiln-dry schedule is required in advance to utilize an unknown species. Terazwa's quick oven-dry method was used to find it and which was confirmed by drying 25 mm thick boards in a kiln. The average green moisture content and the average green specific gravity of Lindera erythrocarpa are 72.3% and 0.53, respectively. Prospective kiln-drying conditions obtained by Terazwa's quick oven-dry method are a initial dry-bulb temperature of $50^{\circ}C$, a initial wet-bulb depression of $4^{\circ}C$ and a final dry-bulb temperature of $75^{\circ}C$, which are in a good agreement with USDA FPL kiln-dry schedule of T5-D4. 25 mm thick boards dried in a kiln with T5-D4 kiln-dry schedule did not have any severe drying defects such as honycombing and warping. A severer kiln-dry schedule of T8-C5 was developed and applied to another kiln-drying run to confirm it.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.81-90
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• 2002

Purpose : To establish and verify the proper and the practical IMRT (Intensity--modulated radiation therapy) patient QA (Quality Assurance). Materials and Methods : An IMRT QA which consists of 3 steps and 16 items were designed and examined the validity of the program by applying to 9 patients, 12 IMRT cases of various sites. The three step OA program consists of RTP related QA, treatment information flow QA, and a treatment delivery QA procedure. The evaluation of organ constraints, the validity of the point dose, and the dose distribution are major issues in the RTP related QA procedure. The leaf sequence file generation, the evaluation of the MLC control file, the comparison of the dry run film, and the IMRT field simulate image were included in the treatment information flow procedure QA. The patient setup QA, the verification of the IMRT treatment fields to the patients, and the examination of the data in the Record & Verify system make up the treatment delivery QA procedure. Results : The point dose measurement results of 10 cases showed good agreement with the RTP calculation within $3\%$. One case showed more than a $3\%$ difference and the other case showed more than $5\%$, which was out side the tolerance level. We could not find any differences of more than 2 mm between the RTP leaf sequence and the dry run film. Film dosimetry and the dose distribution from the phantom plan showed the same tendency, but quantitative analysis was not possible because of the film dosimetry nature. No error had been found from the MLC control file and one mis-registration case was found before treatment. Conclusion : This study shows the usefulness and the necessity of the IMRT patient QA program. The whole procedure of this program should be peformed, especially by institutions that have just started to accumulate experience. But, the program is too complex and time consuming. Therefore, we propose practical and essential QA items for institutions in which the IMRT is performed as a routine procedure.

• Journal of Animal Environmental Science
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• v.6 no.1
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• pp.53-58
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• 2000

A manure management plan is important for all daily operations. This study was conducted to investigate the effect of application level of liquid cattle manure on the soil properties and changes of BOD and COD content in run-off water at the mixtures swards of National Livestock Research Institute RDA Suweon in 1995. The experiment was arranged in a randomized block design with five treatments consisting of no fertilizer chemical fertilizer application of 40, 60 and 80MT/ha as liquid cattle manure. The quantity of run-off for a no fertilizer was the highest of 1,469.4mm but that for a application level of liquid cattle manure of 60MT/ha was the lowest of 1,278.1mm. The change of BOD in run-off for a no fertilizer was the lowest of $19.84m{\ell}/{\;}{\ell}$, but that for a application level of liquid cattle manure of 80MT/ha was the highest of $36.22m{\ell}/{\;}{\ell}$. Change of COD in run-off for a no fertilizer was the lowest of $21.28m{\ell}/{\;}{\ell}$ but that for a application level of liquid cattle manure of 80MT/ha was the highest of $37.51m{\ell}/{\;}{\ell}$. Available phosphorus and total-N content of soil chemical properties was higher at liquid cattle manure than chemical fertilizer.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.89-89
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• 2014

While the current consensus view holds that galaxy mergers are commonplace, it is sometimes speculated that Globular Clusters (GCs) may also have undergone merging events, possibly resulting in massive objects with a strong metallicity spread such as Omega Centauri. Galaxies are mostly far, unresolved systems whose mergers are most likely wet, resulting in observational as well as modeling difficulties, but GCs are resolved into stars that can be used as discrete dynamical tracers, and their mergers might have been dry, therefore easily simulated with an N-body code. It is however difficult to determine the observational parameters best suited to reveal a history of merging based on the positions and kinematics of GC stars, if evidence of merging is at all observable. To overcome this difficulty, we investigate the applicability of supervised and unsupervised machine learning to the automatic reconstruction of the dynamical history of a stellar system. In particular we test whether statistical clustering methods can classify simulated systems into monolithic versus merger products. We run direct N-body simulations of two identical King-model clusters undergoing a head-on collision resulting in a merged system, and other simulations of isolated King models with the same total number of particles as the merged system. After several relaxation times elapse, we extract a sample of snapshots of the sky-projected positions of particles from each simulation at different dynamical times, and we run a variety of clustering and classification algorithms to classify the snapshots into two subsets in a relevant feature space.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.69-74
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• 2011

This paper deals with the detail rotordynamic analysis for the vertical rotor system as development of vertical sea water lift pump for FPSO deep well. In a vertical rotor system, since linearized stiffness and damping coefficients of fluid film bearing are no longer be valid, hence the transient response analysis considering a fluid film force for every journal position in the bearing needs to be required. In this study, the transient response analysis of the proposed vertical pump rotor system was carried out in dry-run and wet-run conditions, respectively. The results show that orbital vibration responses of the rotor system remain stable at rated speed and thereby operating reliability of the vertical rotor system is confirmed. To overcome complexity of calculation pr ocedure and time consuming calculation of transient analysis, the calculating technique of steady-state response analysis is also proposed. The results of steady-state response obtained by applying the proposed technique to the rotor system are good agreement with the reference results, that is, transient responses.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.52-60
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• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• Nuclear Engineering and Technology
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• v.45 no.4
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• pp.427-438
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• 2013

In this paper we discuss spent fuel management options in the Republic of Korea (ROK) from two interrelated perspectives: Centralized dry cask storage and spent fuel pyroprocessing and burning in sodium fast reactors (SFRs). We argue that the ROK will run out of space for at-reactors spent fuel storage by about the year 2030 and will thus need to transition centralized dry cask storage. Pyroprocessing plant capacity, even if approved and successfully licensed and constructed by that time, will not suffice to handle all the spent fuel discharged annually. Hence centralized dry cask storage will be required even if the pyroprocessing option is successfully developed by 2030. Pyroprocessing is but an enabling technology on the path leading to fissile material recycling and burning in future SFRs. In this regard we discuss two SFR options under development in the U.S.: the Super Prism and the Travelling Wave Reactor (TWR). We note that the U.S. is further along in reactor development than the ROK. The ROK though has acquired more experience, recently in investigating fuel recycling options for SFRs. We thus call for two complementary joint R&D project to be conducted by U.S. and ROK scientists. One leading to the development of a demonstration centralized away-fromreactors spent fuel storage facility. The other involve further R&D on a combined SFR-fuel cycle complex based on the reactor and fuel cycle options discussed in the paper.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.233-233
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• 2015

Vu Gia - Thu Bon basin is located in central Vietnam between Truong Son mountain range on the border with Lao in the west and the East Sea in the east. The basin occupies about 10,350 km2 or roughly 90% of the Quang Nam Province and includes Da Nang, a very large city with about 876,000 inhabitants. Total annual rainfall ranges from about 2,000 mm in central and downstream areas to more than 4,000 mm in southern mountainous areas. Rainfall during the monsoon season accounts for 65 to 80% of total annual rainfall. The highest amount of rainfall occurs in October and November which accounts for 40 to 50% of the annual rainfall. Rainfall in the dry season represents about 20 to 35% of the total annual rainfall. The low rainfall season usually occurs from February to April, accounting for only 3 to 5% of the total annual rainfall. The mean annual flow volume in the basin is $19.1{\times}109m 3$. Similar to the distribution of rainfall, annual flows are distinguished by two distinct seasons (the flood season and the low-flow season). The flood season commonly starts in the mid-September and ends in early January. Flows during the flood season account for 62 to 69% of the total annual water volume, while flows in the dry season comprise 22 to 38% of total annual run-off. The water volume gauged in November, the highest flow month, accounts for 26 to 31% of the total annual run-off while the driest period is April with flows of 2 to 3% of the total annual run-off. There are some hydropower projects in the Vu Gia - Thu Bon basin as the cascade of Song Bung 2, Song Bung 4, and Song Bung 5, the A Vuong project currently under construction, the Dak Mi 1 and Dak Mi 4 projects on the Khai tributary, and the Song Con project on the Con River. Both the Khai tributary and the Song Con join the Bung River downstream of SB5, although the Dak Mi 4 project involves an inter-basin diversion to Thu Bon. Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, data from the Vu Gia - Thu Bon River Basin in the central of Viet Nam were analyzed to investigate changes in annual runoff during the period of 1977-2010. The nonparametric Mann-Kendall test and the Mann-Kendall-Sneyers test were used to identify trend and step change point in the annual runoff. It was found that the basin had a significant increasing trend in annual runoff. The hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. This study quantitatively distinguishes the effects between climate variability and human activities on runoff, which can do duty for a reference for regional water resources assessment and management.

• Tribology and Lubricants
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• v.12 no.3
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• pp.107-114
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• 1996

MoS$_{2}$ bonded film was applied to reduction gears, and its lubricating properties were experimentally evaluated in terms of the power transmission efficiency and the frictional noise with a dynamo-typed gear test rig. Tests were performed in both oil lubrication and dry condition where the rotating velocity and loading torque were varied. In dry condition, MoS$_{2}$ bonded films effected the power transmission efficiency to increase about 5%, and the frictional noise level to decrease about 6 dB under the test operating conditions. It well proved that MoS$_{2}$ bonded films were a very effective solid lubricant for reduction gears. In oil lubricating conditions, the frictional properties of the coated gears were mainly governed by the lubricating oil, and lubricating effects of MoS2 bonded films were not evident. The result suggested that lubricating effect of MoS$_{2}$ bonded films would be limited to prevent a damage of reduction gears in the initial run when they were used in oil lubrication conditions.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.340-346
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• 2018

In this study, the effect of elicitors such as yeast extract (YE), methyl jasmonate (MeJA) and salicylic acid (SA) on the accumulation of eurycomanone in Eurycoma longifolia cell cultures were investigated. Suspension cells of E. longifolia was cultured in Murashige and Skoog (MS) medium supplemented with 30 g/L sucrose, 1.25 mg/L naphthaleneacetic acid (NAA) and 1 mg/L kinetin at a shaking speed of 120 rpm. Elicitors were added in the culture at different concentrations and times to stimulate eurycomanone accumulation in the Eurycoma longifolia cells. Eurycomanone content was determined by HPLC with a C18 column, flow rate of 0.8 mL/min, run time of 17.5 min, and a detector wavelength of 254 nm. The stationary phase was silica gel and the mobile phase was acetonitrile: $H_2O$. Non-elicited cells were used as the control. The study showed the effect of different elicitor concentrations, YE at 200 mg/L, MeJA at $20{\mu}M$ and SA at $20{\mu}M$ stimulated high production of eurycomanone. In which, treatment of $20{\mu}M$ MeJA after 4 days of culture resulted in the highest accumulation of this compound (17.36 mg/g dry weight), approximately 10-fold higher than that of untreated cells (1.70 mg/g dry weight).