• Proceedings of the KSR Conference
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• 2011.10a
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• pp.484-489
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• 2011

Heights of a platform above the rail for the passenger train in the country are classified into two categories such as the low level (500mm; mainline) and the high level (1,135mm; metropolitan subway line) platforms. In order to operate similarly both a mainline railroad and a metropolitan subway line, as the requisite door safety system, it is necessary to develop the doorstep equipment of the rolling stock regardless of both the low and high level platforms. In this study, performance requirements of doorstep equipments used for two types of platforms are examined on the supposition that the train only for the low level platform could stop in the both low and high level platforms.

• Proceedings of the KSPS conference
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• 2002.11a
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• pp.86-89
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• 2002

According to Pierrehumbert (1980), two level tones - H and L - are enough in representing intonation of intonational languages. But in Korean, high fall and low fall boundary tones, both of which must be represented as HL％ in intonational phonology as in Jun (1993, 1999), are distinct not only acoustically but also functionally. The same is true in the case of high level and mid level boundary tones, which must be represented as H％ in intonational phonology. In this paper, I conducted two identification tests to provide crucial evidence that H and L are not enough in intonational phonology. The results of the identification tests show that categorical perception occur between high level and low level as well as between high fall and low fall. Based on this fact and the results of the acoustic analyses in Lee (1999, 2000), I strongly propose to adopt one more level tone - M - to represent Korean boundary tones.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.191-199
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• 2016

Conventional two-level Zeta converters have drawbacks, such as high voltage stresses and high current ripples. To address these problems, a three-level Zeta converter that uses a couple inductor is proposed in this study. The proposed converter utilizes the three-level power switching circuit to reduce the voltage stresses and inductor current ripples. Compared with the conventional converter, the proposed converter can improve power efficiency and power density. A 500 W prototype circuit is used to verify the operation and performance of the proposed converter via experimental results.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.586-594
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• 2015

This paper proposes a maximum efficiency operation strategy for three-level T-type inverter in entire operation areas. The three-level T-type inverter has higher and lower efficiency areas compared with two-level inverter. The proposed strategy aims to operate in the maximum efficiency point for the low-voltage and low-power home appliances. The three-level T-type inverter is analyzed in detail, and the two operation mode selection strategy is developed. The proposed algorithm is verified by theoretical analysis and experimental results.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.183-187
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• 2005

A Zero-Voltage-Switching(ZVS) Three-Level Converter realizes ZVS for the switches with the use of the leakage inductance(or external resonant inductance) and the output capacitors of the switches, however; the rectifier diodes suffer from recovery which results in oscillation and voltage spike. In order to solve this problem, this paper proposes a novel ZVS Three-Level converter, which introduces two clamping diodes to the basic Three-Level converter to eliminate the oscillation and clamp the rectified voltage to the reflected input voltage, the proposed ZVS Three-Level converter can be simplified by removing the two freewheeling diodes.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.31-36
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• 2006

By analyzing the Ge 34 core-level photoelectron spectrum, we studied the structure of the $Li/Ge(111)-3\times1$ surface. Two surface related components tying on either side of the main bulk peak were identified in the Ge 3d spectrum. The existence and the position of the two surface components in the core-level spectrum from $Li/Ge(111)-3\times1$ is similar to those of the $Li/Ge(111)-3\times1$, suggesting the similarities in structure of the two surfaces. The core-level photoelectron spectra of the Li-induced $Li/Ge(111)-3\times1$ surface are well consistent with the honeycomb-chain-channel model, which was proposed as the structure of the $Si/Ge(111)-3\times1$ induced by alkali metals.

• Nuclear Engineering and Technology
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• v.36 no.1
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• pp.83-103
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• 2004

The methodological framework of the Level 2 PSA appears to be currently standardized in a formalized fashion, but there have been different opinions on the way the sources of uncertainty are characterized and treated. This is primarily because the Level 2 PSA deals with complex phenomenological processes that are deterministic in nature rather than random processes, and there are no probabilistic models characterizing them clearly. As a result, the probabilistic quantification of the Level 2 PSA CET / APET is often subjected to two sources of uncertainty: (a) incomplete modeling of accident pathways or different predictions for the behavior of phenomenological events and (b) expert-to-expert variation in estimating the occurrence probability of phenomenological events. While a clear definition of the two sources of uncertainty involved in the Level 2 PSA makes it possible to treat an uncertainty in a consistent manner, careless application of these different sources of uncertainty may produce different conclusions in the decision-making process. The primary purpose of this paper is to characterize typical sources of uncertainty that would often be addressed in the Level 2 PSA and to provide a formal guidance for quantifying their impacts on the PSA Level 2 risk results. An additional purpose of this paper is to give a formal approach on how to combine random uncertainties addressed in the Level 1 PSA with subjectivistic uncertainties addressed in the Level 2 PSA.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.169.1-169.1
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• 2005

• East Asian Economic Review
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• v.26 no.4
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• pp.257-277
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• 2022

Does servitization improve manufacturing firms' performance, and in what condition? Following the seminal work of Crozet and Milet (2017), this study analyzes disaggregated firm-level data that covers 40,000 South Korean manufacturing firms surveyed by the Survey of Business Activities of Korea. We compute firm-level servitization intensity with available sales data of each firm by two-digit SIC sub-sectors. We find two novel empirical regularities: Korean servitization intensity distribution shows a very different shape from the French benchmark; Servitized firms tend to perform higher profitability and higher productivity than non-servitized firms.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.463-471
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• 2005

Recently, the number of diabetic patients have been increased with westernized living way and meal habitation. The regulation of blood sugar concentration is very important for diabetic patients to keep homeostasis and, to prevent acute or chronic complications. Epinephrine combined with lidocaine is used in dental clinic extensively. And epinephrine combined with lidocaine also effects on decreasing the blood leakage volume by constricting micro vessle and arteriole. But, So far there are few researches about the effect of epinephrine contained in dental local anesthetic agent on the blood sugar of diabetes during minor oral surgery. The purpose of this study was intended to investigate whether epinephrine which combined with dental local anesthetics influence body glucose level in diabetes patients by glucose monitoring. The subject of this study were 38 diabetic patients and 38 normal adults, each patient was checked body glucose after a meal 2 hours later with resting state, and injection 1:100000 epinephrine with dental lidocaine 54 ml or lidocaine 54 ml only. And then the body glucose level was checked 5 minutes and 30 minutes after injection. The results were analyzed by two way ANOVA test (p<0.05). The results were as follows: In the experimental group 1, the mean of the blood sugar level was 180.3 mg/dl before an anesthetic injection, 182.8 mg/dl after 5minutes of the anesthetic injection and 182.2 mg/dl after 30minutes of the anesthetic injection. The change of the blood sugar level was not statistically by two-way ANOVA tests (p<0.05). In the experimental group 2, the mean of the blood sugar level was 237 mg/dl before an anesthetic injection, 234.5 mg/dl after 5minutes of the anesthetic injection and 231.8 mg/dl after 30minutes of the anesthetic injection. The change of the blood sugar level was not statistically by two-way ANOVA tests (p<0.05). In the controlled group 1, the mean of the blood sugar level was 117.6 mg/dl before an anesthetic injection, 119.1 mg/dl after 5minutes of the anesthetic injection and 129.3 mg/dl after 30minutes of the anesthetic injection. The change of the blood sugar level was not statistically by two-way ANOVA tests (p<0.05). In the controlled group 2, the mean of the blood sugar level was 104.2 mg/dl before an anesthetic injection, 102 mg/dl after 5minutes of the anesthetic injection and 105.3 mg/dl after 30minutes of the anesthetic injection. The change of the blood sugar level was not statistically by two-way ANOVA tests (p<0.05).