• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.11-14
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• 2000

Transparent conducting ITO thin films have been studied and developed for the solar cell substrate or LCD substrate. ITO thin film has been mostly fabricated by high cost sputtering method. In this research, sol-gel method is applied to fabricate ITO thin film at lower cost. The research is focused on the establishment of process condition and development of precursor. Organic sol was made of indium tri-isopropoxide dissolved in ethylene glycol monoethyl ether. The hydrolysis was controled by addition of acetyl acetone. Tin(IV) chloride was added as dopant. Inorganic sol was made of indium acetate dissolve din normal propanol. Spin coating technique was applied to coat ITO on borosilicate glass. The resistivity of ITO thin film was approximately $0.01\Omega{\cdot}cm$ and the transmittance is higher than $90\%$ in a visible range.

• KSBB Journal
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• v.16 no.1
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• pp.71-75
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• 2001

Acanthoside-D, contained in Acanthopanax chilsanensis is known as a ginseng-like substance. This work was focused to set up analytical and preparative conditions for Acanthoside-D purification. The ethanol extract from the powder of the trunk of Acanthopanax chilsanensis was partitioned with hexane. A $\mu$-Bondapak $C_{18}$ (3.9$\times$300 mm, $10\mu\textrm{m}$) column was used to separate Acanthoside-D from the trunk of Acanthopanax chilsanensis. From the experimental results, the mobile phase used for isolating Acanthoside-D from the extract was water/acetonitrile/methanol=80/14/6 %(v/v). The flow rate of mobile phase was 1.0 mL/min, and UV wavelength was fixed at 210 nm. Finally on a semi-preparative column (3.9$\times$ 300 mm, $15\mu\textrm{m}$, Lichrospher 100RP-18) with the same mobile phase composition, the allowable maximum injection volume increased to 250 $\mu\ell$

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.85-90
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• 2010

As the environmental regulation of vehicle emission is strengthened, investigations for $NO_x$ and PM reduction strategies are popularly conducted. Two current available technologies for continuous $NO_x$ reduction onboard diesel vehicles are Selective Catalytic Reduction (SCR) using aqueous urea and lean $NO_x$ trap (LNT) catalysts. The experiments were conducted to investigate the $NO_x$ reduction performance of SCR system which can control the ratio of $NO/NO_2$, temperature and SV(space velocity), and the model gas was used which is similar to a diesel exhaust gas. The maximum reduction efficiency is indicated when the $NO:NO_2$ ratio is 1:1 and the SV is 30,000 $h^{-1}$ in $300^{\circ}C$. Generally, ammonia slip from SCR reactors are rooted to incomplete conversion of $NH_3$ over the SCR. In this research, slip was occurred in 6cases (except low SV and $NO:NO_2$ ratio is 1:1) after SCR. Among 6 case of slip occurrence, the maximum conversion efficiency is observed when SV is 60,000 $h^{-1}$ in $400^{\circ}C$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1277-1282
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• 2015

This paper describes a research for improvement official approval of information processing in national technical qualification. In this paper, we analysis the contents of current exams and propose the new evaluation method of practical exam in information processing fields through grafting new trends of ICT and ability unit, fulfillment criteria in national competency standards(NCS). Also, we have verified the effect of exam through the pilot test. In the future, we will apply the new exams after the revision of guidelines for marking questions by expert group in its duty fields basis on this research

• Journal of the Korean Institute of Gas
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• v.4 no.1 s.9
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• pp.1-8
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• 2000

Third party damage is one of the causes intrimiting the safety of a buried pipelines and it is very important to detect third party damage on pipelines as soon as possible. The purpose of this study is whether third-party damage can be detected by accelerometer sensor and how far the third-party damage signal can propagate. And a pilot experiment was carried out in order to find third-party damage location. As a result, the detected signal's spectum is high frequency at short distances, as the distance is far, the signals in high frequency range are attenuated and those in low frequency range remain. It was also proved that third-party damage within 5.3km distance can be detected by monitoring vibration signals.

• Tribology and Lubricants
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• v.31 no.5
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• pp.213-220
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• 2015

This study evaluates the effect of grooves on the stem part of a plunger on the lubrication characteristics of a fuel injection pump (FIP) by using hydrodynamic lubrication analysis. The current study uses the two-dimensional Reynolds equation to evaluate the changes in lubrication characteristics with variations in clearance, viscosity, and grooves for a laminar, incompressible, and unsteady state flow. This study investigates the lubrication characteristics by comparing the dimensionless minimum film thickness or the film parameter, which is the ratio of the minimum film thickness to surface roughness. The analysis method for the groove section differs depending on the depth of the groove. For instance, in the case of a shallow groove, the film thickness equation considers the depth of the groove, while in the case of a deep grove, it considers the flow continuity. The lubrication characteristics of the FIP are more sensitive to changes in the groove width than to changes in other design variables. Moreover, the application of a groove is more effective under low viscosity conditions. The smaller the distance from the edge of the stem part to the first groove in the case of shallow grooves, the better are the lubrication characteristics of the FIP. In contrast, in the case of deep grooves, the lubrication characteristics of the FIP improve as the distance increases. The application of shallow grooves is more effective for improving the lubrication characteristics than the application of deep grooves.

• The Korean Journal of Pain
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• v.22 no.3
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• pp.224-228
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• 2009

Background: Shoulder arthroscopic surgery is frequently associated with severe postoperative pain, which can be difficult to manage without the use of high-dose opioids. Although an interscalene brachial plexus block (ISBPB) can be used to provide anesthesia for shoulder arthroscopic surgery, its effect using low-dose mepivacaine on postoperative pain management has not been reported. We hypothesized that ISBPB using a low-dose mepivacaine can provide effective postoperative analgesia for shoulder arthroscopic surgery without the need for high-dose opioids and act as a significant motor or sensory block. Methods: This study examined a total of 40 patients, who underwent shoulder arthroscopic surgery, and received ISBPB with 10 ml of normal saline (group NS; n = 20) or 10 ml of 1% mepivacaine with epinephrine 1:200,000 (group MC; n = 20). The block was performed preoperatively. The postoperative pain score, opioid consumption, and side effect were recorded. Results: The visual analog scale scores were significantly lower in group MC than in group NS at 120 minutes after shoulder arthroscopic surgery ($1.9{\pm}1.0$ versus $4.0{\pm}1.4$). Group MC showed significantly lower fentanyl consumption after shoulder arthroscoic surgery than group NS ($27{\pm}32.6$ versus $79{\pm}18.9{\mu}g$). The degree of motor and sensory block after surgery was minimal. Conclusions: ISBPB using low-dose mepivacaine reduced the level of postoperative pain and fentanyl consumption without significant side effects. ISBPB using low-dose mepivacaine is a useful analgesic technique for shoulder arthroscopic surgery.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.127-133
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• 2010

In the ocean area surrounding the Korean Peninsula, the undersea earthquakes have occurred frequently during last decades. The eastern coast of the Korean Peninsula is very vulnerable to tsunami attacks which occur along the Western Coast of Japan. In special, the middle areas of the eastern coast of Korean Peninsula have been damaged due to the Central East Sea Tsunami occurred in 1983. Thus, tsunami hazard mitigation becomes an important issue at eastern coastal communities. The countermeasures against unexpected tsunami attacks are not sufficient because the government policy generally focused on not preventing but recovering. In this paper, a hazard map based on the field survey and tsunami evacuation simulation is developed to mitigate tsunami damage at Imwon port, which was severely damaged during the 1983 Central East Sea Tsunami.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.42-50
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• 2001

In this paper, the reduction of CO₂ gas emission and exhaust gas emission by using the shift of coastal transport from land transport for import-export container cargo was proposed. At first, the domestic CO₂ gas emission, exhaust gas emission and the transportation of import-export container cargo are investigated. And also, we investigated the reduction of CO₂ gas emission and exhaust gas emission by the shift of coastal transport from land transport for the transportation of import-export container cargo between Kyongin area and Pusan Port. Finally, the change of NOx gas emission due to the change of the share of coastal transportation and using the 320TEU container ship are investigated. The research results show that the shift of coastal transport from land transport was effective to reduce the CO₂ gas emission and exhaust gas emission.

• Journal of KIISE:Databases
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• v.37 no.2
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• pp.82-91
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• 2010

Data compression technique is traditional and effective to reduce network traffic. Generally, sensor data exhibit strong correlation in both space and time. Many algorithms have been proposed to utilize these characteristics. However, each sensor just utilizes neighboring information, because its communication range is restrained. Information that includes the distribution and characteristics of whole sensor data provide other opportunities to enhance the compression technique. In this paper, we propose an orthogonal approach for compression algorithm based on a novel feedback diffusion algorithm in sensor networks. The base station or a super node generates the Huffman code for compression of sensor data and broadcasts it into sensor networks. Every sensor that receives the information compresses their sensor data and transmits them to the base station. We define this approach as feedback-diffusion. In order to show the superiority of our approach, we compare it with the existing aggregation algorithms in terms of the lifetime of the sensor network. As a result, our experimental results show that the whole network lifetime was prolonged by about 30%.