• Proceedings of the KIEE Conference
• /
• 1991.11a
• /
• pp.214-218
• /
• 1991

This paper presents a PWM controlled cycloconverter with a DC resonant circuit for Induction heating. This cycloconverter converts commercial frequency power to high frequency power directly. So conversion efficiency improved. Controlling a input reactive power regardless of load power, it has sinusoidal input current waveforms as well as a input. displacement factor at 1.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.283-286
• /
• 1990

This paper presents a PWM controlled cycloconverter with a LC resonant circuit for induction heating. This cycloconverter converts commercial frequency power to high frequency power directly. So conversion efficiency improved. Controlling a input reactive power regardless of load power, it has sinusoidal input current waveforms as well as a input displacement factor at 1.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.4
• /
• pp.194-202
• /
• 1999

Various ways of designing heat sink are available for commercial high power converters and among them, the method of air cooling is the most popular and practical method than any other ones. In this paper, a practical method of cooling high power converter, which includes a method of reducing noise and vibration caused by the fan and a method of estimating the gap and contact resistances existing between the thyristor and heat sink, is presented. Finally, the heat transfer analysis and implementation methods of heat sink for high power converter is presented.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2219-2221
• /
• 2002

This paper describes QA methodologies for developed TBN control system that will be applied to nuclear power plants. The details are the development of QA Manual, QA Procedures, Equipment Qualification Procedure, Commercial Grade Items Dedication, and Software Verification & Validation Plan.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.10a
• /
• pp.285-287
• /
• 2008

This paper represents the electric power load leveling effect of the Light Control System(LCS). The lighting of typical mid-large commercial buildings is the major factor of daytime electric power consumption. Since the national peak power demand occurs in between 11:00 and 16:00, the dimming control of light can contribute the decrease of the power demand We will discuss the load leveling effect of dimming control with LCS.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.11a
• /
• pp.214-215
• /
• 2005

Naval equipments are installed and used for naval vessel with different environmental conditions comparing to the commercial vessel, for example, high engine power per ship displacement size, severe vibration and shock due to high running speed and explosion from naval gun's bombardment and underwater weapons. Therefore, those equipments must be installed on shipboard with small spaces, high ambient temperature around engine room and which are required be fabricated with high resistances of vibration, shock and heat resources. But in case of commercial vessel, the performances of their recent equipments naval have been improved continuously due to the technology development of domestic shipbuilding and shipboard equipment industries, together with the related fundamental industries i.e, metal, steel and electronic industries, to an international level since 1970. With these results, it became possible to unify the specifications of shipboard equipments for the commercial and military vessels(Dual-Use). In this study, vibration and shock test standards for the commercial and military vessels will be compared and reviewed technically.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.10
• /
• pp.1787-1791
• /
• 2010

This paper presents the survey results of the interruption on domestic customer, especially commercial, with primary focus on the cost are presented. General method utilized in quantifying the benefit of reliability on power system is to estimate the Customer Interruption Cost(CIC) associated with the electric service interruption. According to change the circumstance of electricity market by the deregulation and the introduction of new technology, reliable and accurate CIC is required for estimate the applied plan and technology under the circumstance. This paper presents the commercial customer interruption cost is estimated by the survey conducted by KEPCO in 2009. To collect the customer interruption data for calculation of CIC, the survey is conducted. The survey targeting commercial customer around the branch-offices under twelve regional headquarters of KEPCO was carried out.

• Journal of Ginseng Research
• /
• v.31 no.4
• /
• pp.191-195
• /
• 2007

Red ginseng sikhye is one of Korean unique beverages with the addition of effective ingredients of ginseng. Considering economical and mechanical efficiency and quality of sikhye, the optimum conditions for saccharification is to saccharify at 90 degree celsius for 3 hours in the composition of 4% of malt, 20% of steamed rice, and 6% of red ginseng power. The red ginseng sikhye has high soluble solid content over 33% compared with conventional commercial sikhye. On the other hand, ginseng sikhye, which shows low pH, has more or less higher acidity than conventional commercial one. Especially the turbidity of the red ginseng sikhye is much higher than that of commercial sikhye, due to as high amount of rice as 20% compared with 3% in the commercial one. The use of high quantity of rice affected the level of turbidity in red ginseng sikhye. In this study, we wanted to establish optimum conditions for saccharification in manufacturing red ginseng sikhye which contains effective herbal medicinal ingredients maintaining the original taste of traditional sikhye.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.5
• /
• pp.771-782
• /
• 2018

The purpose of this study is to empirically analyze local retailers' recognition of commercial power altered by urban regeneration. For the purpose of this study, analysis is performed on pilot urban regeneration priority projects implemented in the city of Changwon. Although regeneration of commercial districts directly affect the local retailers therein, little research has been carried out to examine how they recognize such changes. This study, therefore, identifies those factors that have influence on the recognition of local retailers who would be aware of the alteration of their commercial power more immediately than others do. Using an ordered logit model, empirical analysis on two pilot projects for Odong-dong and Chang-dong indicates that retailers in Odong-dong are more likely to have a negative recognition toward the altered business areas. For the both districts, recognition of business area alterations is affected with statistical significance by how long they have run their shops, how many employees they hire, and whether they believe that the urban regeneration has resulted in gentrification. For each of the mentioned district, recognition in Odong-dong is significantly impacted by the number of employees and recognized rent changes, while in Chang-dong, the age of retailers and the perceived presence of gentrification have statistically significant influence. Issues found by this study need to be addressed prior to the upcoming 'Urban Regeneration New Deal Project', which then will bring satisfaction to each and every local residents including those retailers.

• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.3085-3099
• /
• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to numerically assess the damage and vibrations of NPP buildings subjected to aircrafts crash. In Part I of present paper, two shots of reduce-scaled model test of aircraft impact on NPP were conducted based on the large rocket sled loading test platform. In the present part, the numerical simulations of both scaled and prototype aircraft impact on NPP buildings are further performed by adopting the commercial program LS-DYNA. Firstly, the refined finite element (FE) models of both scaled aircraft and NPP models in Part I are established, and the model impact test is numerically simulated. The validities of the adopted numerical algorithm, constitutive model and the corresponding parameters are verified based on the experimental NPP model damages and accelerations. Then, the refined simulations of prototype A380 aircraft impact on a hypothetical NPP building are further carried out. It indicates that the NPP building can totally withstand the impact of A380 at a velocity of 150 m/s, while the accompanied intensive vibrations may still lead to different levels of damage on the nuclear related equipment. Referring to the guideline NEI07-13, a maximum acceleration contour is plotted and the shock damage propagation distances under aircraft impact are assessed, which indicates that the nuclear equipment located within 11.5 m from the impact point may endure malfunction. Finally, by respectively considering the rigid and deformable impacts mainly induced by aircraft engine and fuselage, an improved Riera function is proposed to predict the impact force of aircraft A380.