• Journal of the Korean Home Economics Association
• /
• v.28 no.3
• /
• pp.87-103
• /
• 1990

The purpose of this study is to provide basis data to understand the urban housewives' assets management behavior. The result can be summarized as follows: 1. The more urban housewives were educated, the more they were satisfied with methods of assets management. So it turned out that the educational improvement of husbands and wives brought forth the satisfaction of their lives. From this result, we can conclude that more improved education is essential to us. 2. Specifically, age is an important factor of the reasons of assets management. Among housewives below 40 years old. the preparation for purchasing durable goods and more leisure was the main reason for assets management. Among housewives from 40 to 50, the preparation for expenditures of education and marriage of their children was the main reason. Among housewives above 50, the preparation for their retirement was the main reason. As results, we can notice that they don't make a long-range plan positively but they usually prepare expenditures for their seasonable needs. So we have to emphasize on educating them to make a long-range plan.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.335-337
• /
• 2009

A scanning electron microscope(SEM) is a system that visualizes complex surface features. The resolution of SEM is affected by each of equipment components. In this study, we examined the effects of the four factors including the beam current, magnification, voltage and working distance. A statistical analysis was conducted to investigate the main and interaction effects. For a systematic characterization, a $2^4$ full factorial experiment was conducted. The $R^2$ of constructed statistical model was 88.9%. The main effect revealed that the current and working distance are dominant factors. Of the interactions, those between the current and voltage yielded the highest interaction. 3D plots generated from the model were used to explore various parameter effects.

• 한국전산유체공학회:학술대회논문집
• /
• 2010.05a
• /
• pp.464-467
• /
• 2010

Ice accretion on aircraft surface in icing condition induces external shape changes that may result in a hazard factor for aircraft safety. In case of aircraft main wing with high lift equipment, ice accretion is observed around leading edge and flap. During the design phase, location of ice accretion and associated aerodynamic characteristics must be investigated. In this study, icing effects on aerodynamic characteristics of the main wing section of KC-100 aircraft are investigated using an Eulerian-based FENSAP-ICE code in various icing conditions.

• Journal of Korea Port Economic Association
• /
• v.19 no.1
• /
• pp.43-68
• /
• 2003

With development of Asia's economy, the ports in trunk route have increased its handling capacity According to previous studies, main determinants to become hub-port are referred to location, connection inland transport with hinterland, port service availability and efficiency, cost of port handling, socio-economic stability and port information system etc. This study aims to investigate the changes in factors determine port's competitiveness particularly in Asian neighbor ports such as Hong Kong port and Shenzen port, and Singapore port and the Port of Tanjung Pelapas in Malaysia by comparing and analyzing main indicators relating to those ports. In conclusion, main reasons which gained competitiveness by newly developed ports such as Shenzen port and the Port of Tanjung Pelapas were port price and massive hinterland space offered.

• IE interfaces
• /
• v.12 no.2
• /
• pp.266-273
• /
• 1999

This study is concerned with the selection of the main stadium for the World Cup football game to be held in Korea in 2002. Alternatives are (1) new construction of the main stadium at Sangam; (2) and remodeling Jamsil stadium constructed for Olympic in 1988; remodeling Munhak stadium in Inchon. For comparison purpose, we consider four decision attributes (environmental, economy. political and technical factors) under which several detailed sub-attributes are defined. Various multi-criteria decision-making tools such as AHP and TOPSIS are applied to find the best location. Our study results indicate that the best selection is remodeling Jamsil stadium. This appears due to heavy emphasis on economy factor in our analysis.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.1
• /
• pp.256-262
• /
• 2018

This study introduces a novel Soft Switching (SS) Pulse Width Modulated (PWM) AC-DC boost converter. In the proposed converter, the main switch is turned on with Zero Voltage Transition (ZVT) and turned off with Zero Current Transition (ZCT). The main diode is turned on with Zero Voltage Switching (ZVS) and turned off with Zero Current Switching (ZCS). The auxiliary switch is turned on and off with ZCS. All auxiliary semiconductor devices are turned on and off with SS. There is no extra current or voltage stress on the main semiconductor devices. The majority of switching energies are transferred to the output by auxiliary transformer. Thus, the current stress of auxiliary switch is significantly reduced. Besides, the proposed converter has simple structure and ease of control due to common ground. The theoretical analysis of the proposed converter is verified by a prototype with 100 kHz switching frequency and 500 W output power. Furthermore, the efficiency of the proposed converter is 98.9% at nominal output power.

• Journal of the Korean Institute of Landscape Architecture International Edition
• /
• no.1
• /
• pp.37-42
• /
• 2001

In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

• Journal of Power Electronics
• /
• v.12 no.5
• /
• pp.723-730
• /
• 2012

This paper presents a new ZVS single phase bridgeless (Power Factor Correction) PFC, using an active clamp to achieve zero-voltage-switching for all main switches and diodes. Since the presented PFC uses a bridgeless rectifier, most of the time, only two semiconductor components are in the main current path, instead of three in conventional single-switch configurations. This property significantly reduces the conduction losses,. Moreover, zero voltage switching removes switching loss of all main switches and diodes. Also, auxiliary switch turns on zero current condition. The presented converter needs just a simple non-isolated gate drive circuitry to drive all switches. The eight stages of each switching period and the design considerations and a control strategy are explained. Finally, the converter operation is verified by simulation and experimental results.

• Journal of information and communication convergence engineering
• /
• v.3 no.1
• /
• pp.38-42
• /
• 2005

The cyber attacks on the computer system in nowadays are focused on works that do not operate specific application. The main key point that we protect information security system has an access control to keep an application. Most of system has a main function to protect an infrastructure such as hardware, network and operating system. In this paper, we have presented an intrusion tolerance system that can service an application in spite of cyber attacks. The proposed system is based on the middle ware integrating security mechanism and separate function of application and intrusion tolerance. The main factor we use security system in nowadays is service to keep a persistency. The proposed intrusion tolerance system is applicable to such as medical, national defense and banking system.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.6_spc
• /
• pp.736-743
• /
• 2016

This study describes optimization methods for adjustment of helicopter main rotor tracking and balancing (RTB). RTB is a essential process for helicopter operation and maintenance. Linear and non-linear models were developed with past RTB test results for estimation of RTB adjustment. Then global and sequential optimization methods were applied to the each of models. Utilization of the individual optimization method with each model is hard to fulfill the RTB requirements because of different characteristics of each blade. Therefore an ensemble model was used to integrate every estimated adjustment result, and an adaptive method was also applied to adjustment values of the linear model to update for next estimations. The goal of this developed RTB adjustment optimization program is to achieve the requirements within 2 run. Additional tests for comparison of weight factor of the ensemble model are however necessary.