• The Korean Journal of Applied Statistics
• /
• v.30 no.3
• /
• pp.453-462
• /
• 2017

Double propensity score adjustment is an analytic solution to address bias due to incomplete matching. However, it is difficult to estimate the standard error of the estimated treatment effect when using double propensity score adjustment. In this study, we propose two bootstrap methods to estimate the standard error. The first is a simple bootstrap method that involves drawing bootstrap samples from the matched sample using the propensity score as well as estimating the standard error from the bootstrapped samples. The second is a complex bootstrap method that draws bootstrap samples first from the original sample and then applies the propensity score matching to each bootstrapped sample. We examined the performances of the two methods using simulations under various scenarios. The estimates of standard error using the complex bootstrap were closer to the empirical standard error than those using the simple bootstrap. The simple bootstrap methods tended to underestimate. In addition, the coverage rates of a 95% confidence interval using the complex bootstrap were closer to the advertised rate of 0.95. We applied the two methods to a real data example and found also that the estimate of the standard error using the simple bootstrap was smaller than that using the complex bootstrap.

• Korean Institute of Interior Design Journal
• /
• no.16
• /
• pp.106-115
• /
• 1998

Latest modernism shows general idea of phenomenal space through nature of place motility and experience sinceded from standard form and it has general idea of space. therefore this study presents the tension and the relaxation as a method looking for spatal change and value that in spatial experience. For the analysis of work the Conference Pavillon of Tadoa Ando in the furniture company in Vitra Fire Station of Zaha Hidid is analyzed in spatial experence. As the result the result the systematic straight mixture that has a superrimotion with long retangle which the space acts independently and is shown in the drawing of absolutism is formed and collapses theregularity of construction form by decomposition annexation mixing collision and ambivalence. The spatial experiance in this unstable form changes the grade of rank of space by opposite phenomenon by the change of spatial flowing the disorted and vague space that is occurred by superrimotion which has no direction and change of lirht and place and consolidates dynamic strain makes possible to construct against the gravity. And it also creates experienced space thatis reaxed with maintenance of organization of unity harmony, and stsbility.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.853-856
• /
• 2004

Image data processing on the region of interest (ROI) for providing the primary information is needed the view of saving search time and bandwidth over image communications related to web browsing, image database, and telemedicine, etc. Hence, the issue on extracting the region of interest is drawing a plenty of attention for the communication environment with a relatively low bandwidth such as mobile internet. In this paper, we propose a improved standard Maxshift method. The proposed algorithm compress image that includes multiple ROI using Maxshift method in Part 1 of JPEG2000. Simulation results show that proposed method increases PSNR vs. compression ratio performance above the Maxshift method.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.1
• /
• pp.79-84
• /
• 2017

This study suggests the ways of improving the training and licensing system of unmanned aerial vehicles (UAVs), which are drawing attention as a future growth industry, through interviews with domestic experts and examples from advanced countries. In order to improve the system, it was suggested to establish a clear concept about unmanned aerial vehicle pilot, to implement a system to obtain and maintain the UAV pilot license, to develop and supply standard textbooks for acquiring certification, and to prepare certification standards for flight simulators.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.127-131
• /
• 2005

The paper addresses modeling and analysis of a grid-connected photovoltaic generation system (PV system). PSCAD/EMIDC. an industry standard simulation tool for studying the transient behavior of electric power system and apparatus. is used to conduct all aspects of model implementation and to carry out extensive simulation study. An equivalent circuit model of a solar cell has been used for modeling solar array. A PWM voltage source inverter (VSI) and its current control scheme have been implemented. A maximum power point tracking (MPPT) technique is employed for drawing the maximum available energy from the PV array. Comprehensive simulation results are presented to examine PV array behaviors and PV system control performance in response to irradiation changes. In addition, dynamic responses of PV array and system to network fault conditions are simulated and analysed

• Journal of the Korean Institute of Rural Architecture
• /
• v.4 no.1
• /
• pp.87-97
• /
• 2002

This study is aimed at grasping how the farmhouses in Yongdong area continues to be transfigured according to the modernization and urbanization since 8.15 Liberation through the analysis of natural environment and sociocultural environment elements. The farmhouses in Yongdong area before 1960's have had a different spatial structure from those of the other areas because of the characteristics of the climatic, regional, geographic and sociocultural environment elements. The roof improvement promoting law after 1967, the Saemaul Movement since 1971 and the standard drawing of farmhouse after 1972 are transfigured the rural villages, but they were turned up the limitations of their exploits because of the lack of cognition about environment elements. Recently there were appeared the farmhouses which were reflected farmer's decisions in construction after 1980's because former farmhouses were not give consideration to environment elements.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.19 no.5
• /
• pp.723-737
• /
• 1995

The purposes of this study were to investigate 1) the difference of cognitive evaluation on body exposure of female clothing, ann 2) purchase frequency and intention of wearing according to demographic variables. The instrument of this study consisted of response scale and stimuli. Thirty three items of 7.point Likert scale were developed to measure cognitive evaluation of the people who responded. The stimuli were 7 types of clothing, differing exposure parts and style on line drawing. The sample included 450 subjects, consisting of 231 in Seoul and 219 in Chun-nam Province. Statistics applied for analysis were frequency, percentage, mean, standard deviation, correlation, t-test, F-test, Duncan's multiple range test, factor analysis. The Results were: 1. Constructing factors of cognitive evaluation consisted of elegance, sensuality, attraction, individuality. There were significant differences in every factor on each types of clothing. 2. The evaluation toward each types of clothing was influenced by the subjects' sex, age, and residence. 3. Purchase frequency and intention of female subjects' wearing were very low, and there were significant differences on demographic variables.

• Korean Journal of Computational Design and Engineering
• /
• v.9 no.3
• /
• pp.238-245
• /
• 2004

This paper describes an architecture information management system using XML. The purpose of the system is to manage the information stored in standard format, XML, that has many valuable properties. The proposed architecture information consists of project information, drawing information, and material information. Each information is expressed using XML and for each information, XML schema is presented in this paper. In this system, detail information of materials that exists on the supplier's homepage can be displayed when the user of the system wants to check the detail information. Also, drawings stored in STEP data can be browsed in this system. The reports of each information are prepared using XSL. The proposed system shows that XML can be used for a format to store architecture information and various functions can be implemented based on XML related standards.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2002.11a
• /
• pp.11-15
• /
• 2002

3 V, 2.46GHz Low Noise Amplifier (LNA) have been designed for standard 0.35$\mu\textrm{m}$ CMOS process with one poly and four metal layers. This design includes on-chip biasing, matching network and multilayer spiral inductors. The single-ended amplifier provides a forward gain of 20.5dB with a noise figure 3.35dB, and an IIP3 of -6dBm while drawing 59mW total Power consumption

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.426-429
• /
• 2001

Many various products are manufactured which have sculptured surfaces recently. Constructing surface of these models is required technique called reverse engineering. In reverse engineering, a product which has sculptured surfaces is measured and we create surface model to acquire complete model data of object. Measured point data needs preprocess and sampling. Next a set of point data in a plane fit section curve. At last, surface is generated by fitting to section curves. Here we uses sweep surface. Sweep surface is compatible fitting CAD model to drawing. This paper discusses converting approximation of NURBS surface as a standard surface.