• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.1-13
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• 2018

Purpose: The development of compact tractors that can be used in dry fields, greenhouses, and orchards for pest control, weeding, transportation, and harvesting is necessary. The development and performance evaluation of power transmission units are very important when it comes to tractor development. This study evaluates the performance of a driving power transmission unit of a 50 kW multi-purpose narrow tractor. Methods: The performance of the transmission and forward-reverse clutch, which are the main components of the driving power transmission unit of multi-purpose narrow tractors, was evaluated herein. The transmission performance was evaluated in terms of power transmission efficiency, noise, and axle load, while the forward-reverse clutch performance was evaluated in terms of durability. The transmission's power transmission efficiency accounts for the measurement of transmission losses, which occur in the transmission's gear, bearing, and oil seal. The motor's power was input in the transmission's input shaft. The rotational speed and torque were measured in the final output shaft. The noise was measured at each speed level after installing a microphone on the left, right, and upper sides. The axle load test was performed through a continuous equilibrium load test, in which a constant load was continuously applied. The forward-reverse clutch performance was calculated using the engine torque to axle torque ratio with the assembled engine and transmission. Results: The loss of power in the transmission efficiency test of the driving power unit was 6.0-9.7 kW based on all gear steps. This loss of horsepower was equal to 11-18% of the input power (52 kW). The transmission efficiency of the driving power unit was 81.5-89.0%. The noise of the driving power unit was 50-57 dB at 800 rpm, 70-77 dB at 1600 rpm, and 76-83 dB at 2400 rpm. The axle load test verified that the input torque and axle revolutions were constant. The results of the forward-reverse clutch performance test revealed that hydraulic pressure and torque changes were stably maintained when moving forward or backward, and its operation met the hydraulic design standards. Conclusions: When comprehensively examined, these research results were similar to the main driving power transmission systems from USA and Japan in terms of performance. Based on these results, tractor prototypes are expected to be created and supplied to farmhouses after going through sufficient in-situ adaptability tests.

• Analytical Science and Technology
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• v.5 no.4
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• pp.389-399
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• 1992

Liquid Chromatographic behavior of Pd(II) in Isonitrosoethylacetoacetate lmine, $Pd(IEAA-NR)_2$ (R=H, $CH_3$, $C_2H_5$, $n-C_3H_7$, $C_6H_5-CH_2$, $n-C_4H_9$) chelates were investigated by reversed-phase HPLC on Micropak MCH-5 column using methanol/water as mobile phase. The optimum conditions for the separation of $Pd(IEAA-NR)_2$ chelates were examined with respect to the effect of the flow rate, sample solvent, mobile phase strength and column temperature. It wass found that metal chelates were properly eluted in an acceptable range of capacity factor value($0{\leq}log\;k^{\prime}{\leq}1$). The dependence of the logarithm of capacity factor(k') on the volume fraction of water in the binary mobile phase was examined. Also, the dependence of k' on the liquid-liquid extration distribution ratio($D_c$) in methanol-water/n-alkane extration system was investigated. Both kinds of dependence are linear, which susggests that the retention of the electroneutral metal chelate is largely due to the solvophobic effect. Standard adsorption enthalpy changes (${\Delta}H^{\circ}$) and standard adsorption entropy changes (${\Delta}S^{\circ}$) of Pd(II) Isonitrosoethylacetoacetate imine chelates on Micropak MCH-5 column were calculated by measuring capacity factor with changing temperature of the column.

• Elastomers and Composites
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• v.46 no.4
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• pp.335-342
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• 2011

The virgin and recycled polyethylene composites with various ratio of fly ash were manufactured by using a fully intermeshing co-rotating twin screw extruder for the reuse of fly ash from power plant and post-consumed polyethylene. Fly ash were blended with virgin HDPE and recycled polyethylene at the weight fraction of 0 to 40 wt.%. Mechanical properties such as yield strength, abrasion resistance, and slow crack resistance were measured with ISO and ASTM standards. The experimental results for the various composites showed that the elongation at break and the yield stress of the composites decreased with increasing fly ash contents. Generally, the abrasion resistance of PEs decreased with increasing sandpaper grits but the abrasion resistance of the composites increased with fly ash content at finer abrasive surface. The slow crack growth resistance of virgin HDPE, recycled JRPE and the JRPE composite showed higher slow crack growth resistance up to 50% of load at notch depth of 20% and 30%, but KRPE and the KRPE composite showed much lower resistance than virgin HDPE, JRPE and the JRPE composite. Time to break, measured with NCLS test method, of all PEs and the composites satisfies the regulation of Korean Industrial Specification for sewer pipe and support application.

• Journal of Sericultural and Entomological Science
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• v.48 no.1
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• pp.25-27
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• 2006

[ ${\alpha}-Glycosidase$ ] inhibitors slows the velocity of the uptake of monosaccharides in the small intestine by retarding the speed of degradation of disaccharides to monosaccharides, which made it possible to develop ${\alpha}-glycosidase$ inhibitors as the antihyperglycemic ('antihyperglycemic' means 'blood-glucose-level-lowering') reagent for the diabetic patients such as acarbose and miglitol. Twenty kinds of ${\alpha}-glycosidase$ inhibitors have been reported to exist in mulberry, Morns alba, and some of them are also found in the silkworm, Bombyx mari, as the result of its daily feeding of mulberry leaves as the sole diet. 1-Deoxynojirimycin (DNJ), one of the most potent ${\alpha}-glycosidase$ inhibitor, is the most abundant among polyhydroxylated alkaloids with ${\alpha}-glycosidase$ inhibiting activity in both M alba and B. mari, therefore considered the antihyperglycemic criterion of the mulberry- or silkworm-based neutroceutical products. DNJ is thought to be accumulated in the body of silkworm because the its concentration in the silkworm body is two to three times as much as that in the mulberry leaves. Eighteen silkworm F1 varieties have been recommended for industrial rearing in Korea by some standards such as pathological strength. DNJ concentration in 18 recommendedwere measured at 3rd day in the 5th instar after lyophilization to determine the varieties that accumulates DNJ in its body most. GeumOk-Jam was the highest in the DNJ concentration of 5.45 mg/gDW among the recommended F1 varieties.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.415-423
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• 2006

As the shortage of natural & good quality aggregate for concrete, it is needed development of alternative aggregate. At the present time, the crushed sand is widely used among the alternation aggregate, and the usage of crushed sand will be increased more and more. Generally, crushed sud is produced with wet process in domestic, but some manufacturing companies which are handicapped with local restrict are produced by dry process. In this study, analyzing the facilities of dry crushed sand, the quality properties of dry crushed sand was done by Korean Industrial Standards. Based on the quality results of dry crushed sand, the experiment of concrete with the dry crushed sand which is substitute for sea sand was done. As the results of basic qualities, the amount of 0.08 mm sieve passing ratio was over KS criteria, and the fineness modulus was higher than sea sand, and the other physical properties of dry crushed sand was similar to sea sand. The results of concrete experiment, according to the substitutive ratio of dry crushed sand is increased, the slump and air content of concrete was decreased by increase of fine particles of dry crushed sand, and the unit weight content, compressive & tensile strength of concrete were increased on the contrary. The physical properties of concrete used dry crushed sand were showed same tendency without relation to W/B. Consequently, if the fine particle contents of dry crushed sand was lower, it is judged that dry crushed sand is no problem to use for concrete aggregate and the amount of usage will be increased.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.777-783
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• 2006

This study has focused on the possibility for recycling of tailings from the Sangdong tungsten mine as powder(TA) of self-compacting concrete(SCC). The experimental tests for slump-flow, time required to reach 500 mm of slump flow(sec), time required to flow through V-funnel(sec) and filling height of U-box test(mm) were carried out in accordance with the specified by the Japanese Society of Civil Engineering(JSCE). The results of this study, slump-flow of SCC was satisfied a prescribed range. And time required to reach 500 mm of slump flow(sec) and time required to flow through V-funnel(sec) decreased with increasing replacement of TA. But filling height of U-box test(mm), replacement of TA up to 30% were satisfied a prescribed range. The mechanical properties including compressive strength, splitting tensile strength and elastic modulus were checked with the requirements specified by Korean Industrial Standards(KS). The compressive strength of SCC decreased with increasing replacement of TA, splitting tensile strength and elastic modulus were similar to those of normal concrete. The fundamental durability was reviewed through the dry shrinkage rate and accelerated carbonation tests. As the result dry shrinkage rate and accelerated carbonation depth increased with increasing replacement of TA.

• Toxicological Research
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• v.28 no.1
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• pp.25-31
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• 2012

The purpose of this study was to determine the acute pulmonary toxicity of metallic silver nanoparticles (MSNPs, 20.30 nm in diameter). Acute pulmonary toxicity and body distribution of inhaled MSNPs in mice were evaluated using a nose-only exposure chamber (NOEC) system. Bronchoalveolar lavage (BAL) fluid analysis, Western blotting, histopathological changes, and silver burdens in various organs were determined in mice. Mice were exposed to MSNPs for 6 hrs. The mean concentration, total surface area, volume and mass concentrations in the NOEC were maintained at $1.93{\times}10^7$ particles/$cm^3$, $1.09{\times}10^{10}\;nm^2/cm^3$, $2.72{\times}10^{11}\;nm^3/cm^3$, and 2854.62 ${\mu}g/m^3$, respectively. Inhalation of MSPNs caused mild pulmonary toxicity with distribution of silver in various organs but the silver burdens decreased rapidly at 24-hrs post-exposure in the lung. Furthermore, inhaled MSNPs induced activation of mitogen-activated protein kinase (MAPK) signaling in the lung. In summary, single inhaled MSNPs caused mild pulmonary toxicity, which was associated with activated MAPK signaling. Taken together, our results suggest that the inhalation toxicity of MSNPs should be carefully considered at the molecular level.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.98-106
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• 1999

This study was carried out to analyze the mechanical properties of soil for counterplan of recovery construction and the slope stability on fill slope of Sang-gul forest road in Mt. Gari. To analyze the mechanical properties of apparent soil on fill slope in forest road, various soils such as soil, gravelly sandy soil, weathered rock were used as experimental sample in this study. In each experimental sample, particle size distribution test, liquid limit test, plastic limit test, and specific gravity test were carried by Korean industrial standards(KS F 2302, KS F 2303, KS F 2304, KS F 2306, KS F 2308). Through the results of soil particle size distribution analysis, soil moisture content analysis, and specific gravity analysis, soil texture, uniformity coefficient, curvature coefficient, dry density and specific gravity were able to be determined in sampling site. As a results in this study, soil was classified as SP, SW, GP by Unified Soil Classification Standard (USCS). specific gravity and dry unit weight of soil have the value range of 2.52~2.60 and 1.39~1.43, respectively. Also plastic index showed non plastic condition.

• Journal of Arbitration Studies
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• v.21 no.2
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• pp.85-112
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• 2011

These days utilization of copyright in daily life and economic activities is becoming more important than ever, and IT technology is developing day by day. Along with those fact, copyright infringement and dispute is naturally increasing. This thesis dealt with the 3 different issues of ADR on copyright. The First part, introduce ADR system that was performed by Korea Copyright Committee according to Copyright law. This paper evaluate the committee's efforts to provide resolution of copyright disputes via conciliation was effective. So it needs to be look over several countries' ADR, beside conventional judicial remedy. And Korea's copyright conciliation system which is successfully operating also introduced. Second, In many countries, including South Korea are take advantage of conciliation as the way to settle down the dispute over copyright. Furthermore, looked over if we can use arbitration as tool to settle dispute or not. Currently in Korea, patent dispute is handled by Industrial Property Dispute Conciliation Committee(The Invention Promotion Act Ch.5) and Layout-design Review and Mediation Committee(The Act on the Layout-designs of Semiconductor Integrated Circuits Art.29-34), but using performance of those two committee is still too low. In comparison, the copyright committee, a affiliation organization of the ministry of culture, sports and tourism has much more result in conciliation compare with patent dispute. Copyright disputes has arbitrability of it's subject-matter and many regulating organs are interested in it. (especially, binding of arbitral award and final resolution). Take advantage of both conciliation and arbitration could be good way to resolve copyright disputes. Third, the writer look at the proposal on the creation of Northeast Regional Center for Intellectual Property ADR. Because of the nature of copyright and rapid development of internet technology, international use of work become more frequent and accordingly infringement cases are increasing. The role of commercial arbitration regimes and institutions which has progressed significantly worldwide level, but which has only just begun in the intellectual property ADR area, leads also to a clash of often very different legal cultures and protection in a market economy. International cooperation in regional area with conflict interests becomes an important alternative. But it will depend on the building of regional institutions and mechanisms. The feasibility of this proposal and preconditions were examined. Establishment of new international organization requires a lot of time, cost and efforts. And risk of failure is much too high. Therefore factual, statistical review should be preceded. In addition, technical measures, such as on-line arbitration is necessary to review also. Furthermore in order to establish new organization, the relative law, legal environment, public sentiment and international compliance must be carefully considered with factual review about the needs and economic benefits of each country Yet on complex regulatory matters such as IP and ADR, a great deal of the potential benefits from international standards arises not from the international legal framework nor even the formal content of national legislation, but from the informed and effective use made of the possibilities within the system, including by policymakers and regulators.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.92-99
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• 2020

Linked treatment refers to a system that relieves the burden of the business by linking high concentrations of wastewater such as human waste, manure, leachate, and other industrial wastewater to nearby municipal wastewater treatment plants(MWTPs). In 2018, 187 MWTPs, which are about 4.5% of the total domestic MWTPs, have implemented a linked treatment system, but local governments are having difficulties in operating sewage treatment due to lack of reasonable cost estimation standards. Therefore, we proposed an improvement plan to solve the problem in the calculation method that currently imposes linked wastewater. To this end, the effects and correlations of the linkage treatment system on the sewage treatment unit were analyzed, and among them, the main factors with the highest correlation were applied to the improvement plan. As a result, an improvement plan that improved three parts of the existing calculation method was presented, and the calculation method and the calculation case using the existing literature values were also presented. This can be used as a basis for future reference by local governments to implement linkage treatment, and to revise local sewerage ordinance and is believed to be helpful in operating a rational linkage system.