• Journal of IKEEE
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• v.23 no.2
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• pp.571-579
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• 2019

Visible light communication (VLC) performs illumination and communication simultaneously, thus it is important to prevent the flicker due to the optical power variation during data transmission and at the same time to have dimming control capability. In this paper, we used Manchester code for flicker-prevention and dimming control. In the transmitter, the duty factor of the Manchester code was used for controlling the LED illumination. In the receiver, the edge-spike signals of an RC-high pass filter were used for recovering the Manchester code while preventing the adjacent noise light. In experiments, the LED light was kept flicker-free and the average optical power was controlled in the range of 8~68 % of the continuous wave (CW) LED light by changing the duty factor of the Manchester code.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.1
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• pp.15-24
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• 2012

In this paper, we suggest the dynamic-response-free SMPS using a new high-resolution DPWM generator based on switched-capacitor delay technique. In the proposed system, duty ratio of DPWM is controlled by voltage slope of an internal capacitor using switched-capacitor delay technique. In the proposed circuit, it is possible to track output voltage by controlling current of the internal capacitor of the DPWM generator through comparison between the feedback voltage and the reference voltage. Therefore the proposed circuit is not restricted by the dynamic-response characteristic which is a problem in the existing SMPS using the closed-loop control method. In addition, it has great advantage that ringing phenomenon due to overshoot/undershoot does not appear on output voltage. The proposed circuit can operate at switching frequencies of 1MHz~10MHz using internal operating frequency of 100 MHz. The maximum current of the core circuit is 2.7 mA and the total current of the entire circuit including output buffer is 15 mA at the switching frequency of 10 MHz. The proposed circuit has DPWM duty ratio resolution of 0.125 %. It can accommodate load current up to 1 A. The maximum ripple of output voltage is 8 mV. To verify operation of the proposed circuit, we carried out simulation with Dongbu Hitek BCD $0.35{\mu}m$ technology parameter.

• Journal of Korea Trade
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• v.23 no.5
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• pp.66-86
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• 2019

Purpose - This paper describes the use of trade preferences under the EU-Korea free trade agreement (FTA) and empirically examines potential reasons for the less than full use, using data on daily EU imports from Korea at the product level. Design/methodology - We employ a probit model to analyse the relationship between the use of trade preferences on the one hand and variables such as potential duty savings, rules of origin and the characteristics of the good traded (intermediate input or final product) on the other. Findings - The paper finds that EU imports from Korea make good use of trade preferences with an overall preference utilisation rate of close to 90% in 2016, which is up from about 80% in 2012. It further shows that potential duty savings influence preference utilisation positively and that more than one quarter of the observations in our sample made use of preferences under EU-Korea FTA in 2012, despite duty savings standing at €10 or less. Originality/value - The finding that a non-negligible share of observations use preferences even when the duty savings are low has not yet figured in the literature. We further show how preference utilisation rates differ by importing EU Member State and by section of the Harmonised System and estimate the marginal impact of an increase in potential duty savings on the preference utilisation rate by broad product group, which is novel.

• Korea Trade Review
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• v.45 no.1
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• pp.203-219
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• 2020

The parties shall perform all actions necessary for the proper and expeditious conduct of arbitral proceedings. This includes complying without delay with any determination of the tribunal as to any and all procedural or evidential matters, or with any order or directions of the tribunal, and where appropriate, taking without delay any necessary steps to obtain a decision of the court on a preliminary question of jurisdiction or law. The parties are free to agree on the powers of the tribunal in case of a party's failure to do something necessary for the proper and expeditious conduct of the arbitration. The parties' general duty may be based on agreements, such as the duty not to ask the court for a dispute, the duty to carry out arbitral awards, and the duty of confidentiality. In this study, as a premise, after confirming the discussion related to Article 40 (general obligations of the parties) of the law, the arbitral tribunal will analyze the authority to execute it based on Article 41. As a matter of fact, in LMAA Terms 2017, the parties want to analyze what is required in order to proceed effectively.

• The Journal of Information Technology
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• v.4 no.2
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• pp.103-115
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• 2001

This paper seek to clarify a narrow set of policy issues relating to the international trade aspects of electronic commerce. It focuses, in particular, on the WTO decision not impose customs duties on electronically delivered products. The decision on duty-free commerce is intended to contribute to the growth of electronic commerce by providing a guarantee of open trading conditions, but the significance of the decision may have been exaggerated. In particular, the prohibition of customs duties does not ensure continued open market access for electronically delivered products and may even prompt recourse to inferior instruments of protection. Accordingly, barrier-free electronic commerce would be more effectively secured by deepening and widening the limited cross-border trade commitments under the GATS and by clarifying and strengthening certain GATS disciplines.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.328-338
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• 2013

This study aims at exploring the characteristics of interior design of the Cruise line running Korea, Japan and China, and the satisfaction level of the Korean passengers for the interior design. Literature review and the physical traces of the cruise ship interior including 4 types of cabins and public spaces such as main hall, restaurants, outdoor swimming pool, jogging track, theater, meeting room, duty-free shop were performed. Also, the questionnaire to the passengers were used to understand their preferences and satisfaction level for each space. The results show that the passengers are very satisfied with the color and atmosphere of the cabin, while they complain the inconvenience of the bathroom size. Also in the public space, they prefer western classic style and modern style rather than Asian or Korean style. This means that they want the exotic feeling coming out of home. Also they prefer buffet restaurant, duty-free shop, theater, observation platform compared to other public spaces. However, the problem is that there are no place for the Korean family members with young children except for the outdoor pool. The interior and the program should be redesigned for the public spacs such as cinema room, family karaoke and internet-free room for Korean passengers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.437-443
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• 1998

Automobile company tries to reduce the inertia of powertrain to increase the fuel efficiency and increase the engine power every year to make the high speed driving possible at full load condition. These cause the torsional vibration of powertrain. But the demand about ride comfort improvement is increased constantly, so torsional vibration of powertrain become an emergency problem to be cured. This study is a basic research to reduce the torsional vibration of powertrain at driving condition. First, the heavy duty powertrain is characterized as a vibrating system. Its natural frequencies and mode shapes are reviewed. Second, by comparison of simulation results and experiment results, validity of developed model is verified. Finally, the couterplan which can reduce the torsional vibration by mode analysis and parameter modification is suggested.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.9-15
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• 2009

In this paper, we invented a new structure of fast ATC(Automatic Threshold Control) circuit. Using the structure we made a new burst-mode limiting amplifier with fast ATC function using commercial $0.8{\mu}m$ BiCMOS technology. It's ATC function worked so fast that even the first bit of burst-data could be detected, which confirmed that the new structure was useful for fast ATC. However, in the beginning of a burst, distortions in duty-cycle occurred and increased up to 59% of duty-cycle as amplitude of input signal increased. But we confirmed that after 10 cycles passed, duty-cycles was staying below 52% of duty-cycle for any magnitude of input signal.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.133-141
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• 2013

The objective of this study is to empirically examine the effect that social welfare officials' awareness of welfare, who play the core role in delivering public welfare service, has on their sense of duty value and duty efficiency. The implications this study suggests are as follows; First, this study has a meaning in that it empirically proved the social welfare officials' awareness level of welfare. Second, this study provided the specific theoretical basis for the approaches and alternatives for the need to improve social welfare officials' awareness of welfare and operate the desirable welfare policy and system, by examining the effect that social welfare officials' awareness of welfare has on their sense of duty value and duty efficiency. Third, we can find the political implication from this study that welfare policy should be established and operated toward the direction of enhancing equalization effect of welfare system, and minimizing free ride or hampering the will to work, if we intend to improve social welfare officials' awareness of welfare. Fourth, this study presented the need to improve the work system of social welfare officials, through the fact that the shorter their work period is, the lower sense of welfare, duty value and duty efficiency they have. Based on the study results above, we suggest the activation of studies on social welfare officials' awareness of welfare, the need to regularly educate social welfare officials about welfare policy, system and value, the need to improve social welfare officials' positive awareness of welfare and their duty performance through deciding welfare policy toward the direction of enhancing social equality and equalization, and the need to improve social welfare officials' work system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.74-87
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• 2011

This paper tried to research the relationship among the passenger's satisfaction and expectation of in-flight service quality, overall satisfaction and passenger's Loyalty by emphasizing on two groups of passengers and cabin crews from K-airline to find out which service quality area should be focused on for pursuing premium in-flight service. Such six service quality areas as in-flight equipment, food&beverage, duty-free sales, service ability, service image and specialized service were conceived and survey questions were made based on relevant previous researches. The analysis has used the data of 281 passengers and 336 cabin crews from K-airline. According to the analysis, in physical service factors, passengers perceive satisfaction from duty-free sales contributes to overall service satisfaction. However, cabin crews believed in-flight equipment and food&beverage are important to overall service satisfaction. In human service factors, both groups seemed to agree service ability and service image have a positive impact on overall service satisfaction. Among service satisfaction factors, the customer's satisfaction from cabin crew's service ability(service response, professional knowledge and foreign language skill) is also proven to be directly connected to customer loyalty.