• Journal of the Korean Society of Costume
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• v.52 no.8
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• pp.15-27
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• 2002

To set the measurements of bras for women in their 20s, considering the comfortableness in wearing and tightness, this paper conducted a questionnaire survey concerning breasts and bras as well as measurements of body and contact surface pressure. Easier and more accurate method of determining cup sizes based on the breast circumference is recommended to make up for the problem of current bra size system that can falsely measure cup sizes. Lower chest circumference was set at 5 cm equal intervals, and the breast circumference applicable to the cup size was set starting from the standard, 18 cm (A-cup), at 2 cm equal intervals, which gave the best coverage (88.1%).

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.155-157
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• 2005

We propose a new category of hybrid multi-layer neural networks with hetero nodes such as Fuzzy Set based Polynomial Neurons (FSPNs) and Polynomial Neurons (PNs). These networks are based on a genetically optimized multi-layer perceptron. We develop a comprehensive design methodology involving mechanisms of genetic optimization and genetic algorithms, in particular. The augmented genetically optimized HFPNN (namely gHFPNN) results in a structurally optimized structure and comes with a higher level of flexibility in comparison to the one we encounter in the conventional HFPNN. The GA-based design procedure being applied at each layer of HFPNN leads to the selection of preferred nodes (FPNs or PNs) available within the HFPNN. In the sequel, two general optimization mechanisms are explored. First, the structural optimization is realized via GAs whereas the ensuing detailed parametric optimization is carried out in the setting of a standard least square method-based learning. The performance of the gHFPNNs quantified through experimentation where we use a number of modeling benchmarks-synthetic and experimental data already experimented with in fuzzy or neurofuzzy modeling.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.10
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• pp.936-941
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• 2000

Advanced space transportation systems, such as the National Aerospace Plane or an Orbital Transfer Vehicle, have atmospheric maneuvering capabilities. For such vehicles the use of aeroassisted orbital transfer from a high Earth orbit to a low Earth orbit, with unpowered flight in the atmosphere, has the potential for significant fuel savings compared to exoatmospheric Hohmann transfer. However, to exploit the fuel savings that can be achieved by using the Earths atmosphere to reduce the vehicles energy, a guidance law is required, and it must be able to handle large unpredictable fluctuations in atmospheric density, on the order of ${\pm}$50% relative to the 1962 US Standard Atmosphere. In this paper aeroassisted orbital transfer is considered as a differential game, with Nature controlling the atmosphere density to yield a worst case (min-max fuel required) atmosphere, from which the guaranteed playable set boundary are achieved. Inside the playable set, it is guaranteed that the vehicle achieves the optimal atmospheric exit condition for the minimum fuel consumption regardless of the atmospheric density variations.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.137-146
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• 2005

In parametric approach to a signature verification, it generally uses so many redundant features unsuitable for each individual signature that it causes harm, instead. This paper proposes a method of determining personalized weights of a feature set in signature verification with parametric approach by identifying the characteristics of each feature. For an individual signature, we define a degree of how difficult it is for any other person to forge the one's (called 'DFD' as the Degree of Forgery Difficulty). According to the statistical characteristics and the intuitional characteristics of each feature, the standard features are classified into four types. Four types of DFD functions are defined and applied into the distance calculation as a personalized weight factor. Using this method, the error rate of signature verification is reduced and the variation of the performance is less sensitive to the changes of decision threshold.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.146-153
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• 2007

Weight reduction for automobile components has been sought to achieve fuel efficiency and energy conservation. There are two approaches in reducing their weights. One is by using material lighter than steel, and the other is by redesigning their structures. The latter has been performed by adopting hydroforming, tailor weled blank, optimization, etc. In this research, the kriging approximation method and simulated annealing algorithm are applied to the design of a front door made by TWB (Tailor Welded Blank) technology. The design variables are set up as the thicknesses of parts and the positions of parting lines. A thickness set considered as a design variable of each part is not arbitrarily determined but selected from standard products, so it is a discrete set. This research presents the discrete and continuous structural optimization method for an automotive door design.

• Bulletin of the Korean Mathematical Society
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• v.43 no.2
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• pp.293-297
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• 2006

Using the concept of codes on ordered sets introduced by Brualdi, Graves and Lawrence, we consider perfect codes on the ordinal sum of two ordered sets, the standard ordered sets and the disjoint sum of two chains.

• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.633-641
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• 1996

Let $P_J$ be a standard parabolic subgroup of a Chevalley group G and $U_J$ the unipotent radical of $P_J$. In this paper, we find a certain partition of the set of roots corresponding to root subgroups generating $U_J$ and investigate some properties of the partition.

• Journal of the Korean Statistical Society
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• v.5 no.1
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• pp.19-28
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• 1976

In empirical study for fitting a multiple linear regression model for successive cross-sections data observed on the same set of independent variables over several time periods, one often faces the problem of poor $R^2$, the multiple coefficient of determination, which provides a standard measure of how good a specified regression line fits the sample data.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.6
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• pp.559-574
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• 2016

Based on air quality monitoring data ('10~'14) of Suwon City provided by the Korean Department of Environment, a fundamental statistic for 5 criteria pollutants such as $SO_2$, CO, $NO_2$, $O_3$, and $PM_{10}$ was initially investigated. The purpose of this paper was to review the ambient air quality standards(AAQS) of Korea, the U.S.A. and the EU and further to assess the degree of standard strength by the achievability of the AAQS comparing each national standard. Since the level and the way of standards for each air pollutant are various among countries, it is difficult to determine the degree of relative attainment using the same set of data above. Further when all the areas having bad air quality for a specific pollutant are classified as non-attainment case, it is more difficult to assess the degree of standard strength. Thus we introduced a new concept called the average concentration distance (ACD) to quantitatively estimate the strength. As results, the Korean 1-hr $NO_2$ AAQS is slightly stronger than the US standard and weaker than the EU standard. The Korean $O_3$ standard is strongest; however, the Korean $PM_{10}$ standard is weakest. Furthermore the equivalent levels of 8-hr $O_3$ standards in the U.S.A. and the EU were respectively estimated as 97.5 and 95.7 percentiles of the Korean standard with maintaining the existing standard of 60 ppb.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.204-205
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• 2020

Construction Standard Unit Price is the unit price calculated based on the market price for work items in construction projects that have already been conducted. It is used as basic data for calculating the budget price of public construction projects. In the Construction Standard Unit Price Book implemented in the second half of 2020, there are 1,810 types of unit prices. Since 2017, 100-150 construction standard unit prices have been revised semiannually (on January 1 and July 1 of each year) through Construction Site Surveys. Other work items have been set based on the rate of inflation during the corresponding period. Later in 2020, this procedure was changed, with on-site survey period extended to one year to strengthen the construction standard unit price investigation. The revisions previous announced during the second half of the year were changed only to reflect the price inflation rates. With such changes in the revisions to construction standard unit prices, one important issue that was raised: The timing of announcing the revisions during the second half of the year (reflecting the price inflation rates). The market unit wage, which is the unit price standard of labor cost that takes up a large part of the construction cost, is announced in January and September. The figures announced in September is reflected on the construction standard unit price four months later in January, but the market unit wage announced in January is reflected only six months after in July, which causes a timing issue. As such, the current study analyzed problems rising from the changed timing of the announcements of the construction standard unit price during the second half of the year, in addition to analyzing their impact on public construction projects.