• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.1
• /
• pp.63-69
• /
• 2000

Le fort II osteotomy is much useful technique to correct the midfacial hypoplasia including nasomaxillary complex especilly in patient with dish face appearance. Not in simple orthognathic surgery but in Le Fort II osteotomy, the standardization of prognostic value is essential in treatment planning to achieve satisfactory postoperative results. According to pervious reports, the ratio of soft tissue change to hard tissue movements varies as to different surgical methods and different facial regions. But there are few report about the ratio of soft tissue change to hard tissue movement following Le Fort II osteotomy. So we tried to develop standarized soft tissue surgical treatment objective. We have followed up 16 patients, who had received Le Fort II osteotomy by one operator from 1990 to 1996, one year postoperatively. In cephalometrics, we used Frankfort line as horizontal reference line, and vertical reference line as one drawn from Sella to horizontal line perpendicularly. The landmarks are G to soft tissue G, N on reference line to soft tissue N, ANS to Pn and A to Sn. The results are as follows. 1. The value of soft tissue change to hard tissue movement showed positive correlation, having statistical significancy at G, N2, N3 point. 2. At G, N2, N3 point, the ratio of soft tissue change to hard tissue movement was 0.51, 0.98 and 0.80 respectively and showed statistical significancy, while at N1, ANS, A point, that was 0.72, 0.49 and 0.26 but didn't showed statistical significance. 3. This result shows much the same change of the soft tissue change to hard tissue movement on the upper nasomaxilla, and less the same change on the lower maxilla and so the Le Fort II osteotomy can be recommended as a reliable effective operation method for correction of nasomaxillary retrusion.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.19 no.1
• /
• pp.62-68
• /
• 2009

Two new generation gap models with modified parent-centric recombination(PCX) operator are proposed. First, the self-adaptation generation gap(SGG) model is a control method that keeps a replaced probability of parents by offspring to a certain level which obtains better performance. Second, virtual cluster generation gap(VCGG) is provided to extend distances among parents using clustering, which causes it to diversify individuals. In this model, distances among parents can be controlled by size of clusters. To demonstrate the effectiveness of our two proposed approaches, experiments for three standard test problems are executed and compared to most competing current approaches, CMA-ES and Generalized Generation Gap(G3) with PCX. It is shown two proposed methods are superior to consistently other approaches in the study.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.8 no.1
• /
• pp.6-10
• /
• 2008

In this paper, we introduce the concept of fuzzy (r, s)-adherence points, fuzzy (r, s)-accumulation points and fuzzy (r, s)-derived sets in double fuzzy topology. We investigate some of their properties. The relationship with double fuzzy closure operator was studied.

• Honam Mathematical Journal
• /
• v.30 no.1
• /
• pp.197-203
• /
• 2008

We show the existence of the unique solution of the following system of the nonlinear wave equations with Dirichlet boundary conditions and periodic conditions under some conditions $U_{tt}-U_{xx}+av^+=s{\phi}_{00}+f$ in $(-{\frac{\pi}{2},{\frac{\pi}{2}}){\times}R$, ${\upsilon}_{tt}-{\upsilon}_{xx}+bu^+=t{\phi}_{00}+g$ in $(-{\frac{\pi}{2},{\frac{\pi}{2}}){\times}R$, where $u^+$ = max{u, 0}, s, t ${\in}$ R, ${\phi}_{00}$ is the eigenfunction corresponding to the positive eigenvalue ${\lambda}_{00}$ of the wave operator. We first show that the system has a positive solution or a negative solution depending on the sand t, and then prove the uniqueness theorem by the contraction mapping principle on the Banach space.

• Journal of applied mathematics & informatics
• /
• v.7 no.3
• /
• pp.833-842
• /
• 2000

Consider the even-order neutral difference equation (*) ${\delta}^m(x_n{-}p_ng(x_{n-k}))-q_nh(x_{n-1})=0$, n=0,1,2,... where $\Delta$ is the forward difference operator, m is even, ${-p_n},{q_n}$ are sequences of nonnegative real numbers, k, l are nonnegative integers, g(x), h(x) ${\in}$ C(R, R) with xg(x) > 0 for $x\;{\neq}\;0$. In this paper, we obtain some linearized oscillation theorems of (*) for $p_n\;{\in}\;(-{\infty},0)$ which are discrete results of the open problem by Gyori and Ladas.

• Journal of Korean Port Research
• /
• v.9 no.2
• /
• pp.1-8
• /
• 1995

Generally, berth assignment problem has conflicting factors according to the interested parties. In the view of shipping company, it is desirable that berth assignment is made according to the order of arrival. But in the view of port operator, it is better to be assigned regardless the order of arrival to promote the efficiency of berth operation. Thus, it is necessary to establish berth assignment planning which reflects both of interests in a practical situation. This paper aims to develop a reasonable berth assignment algorithm in a container terminal by considering the prescribed factors, and suggests three types of models minimizing the objective functions such as total port staying time, total mooring time and total maximum mooring time by using MPS concept. These models are formulated by 0-1 integer programming and min-max type function, but as the number of variables increases, an optimal solution cannot be achieved easily within a desired computational time. Thus, to tackle this problem this paper proposes a heuristic algorithm, and also the heuristic algorithm proposed in this paper is verified through the several examples.

• Journal of Intelligence and Information Systems
• /
• v.8 no.1
• /
• pp.63-74
• /
• 2002

This paper presents an application result of on-line fault diagnosis system for glass melting furnace using a fuzzy expert system. Operators maintain the furnace using the furnace Knowledge and experience, which directly influence the furnace and glass product. Firstly, knowledge and experience is achieved and analyzed to implement the furnace Knowledge and experience into fuzzy expert system. The acquired Knowledges determined as a crisp rule or a fuzzy rule to expect its characteristics. And, a linear regression is used as the input of fuzzy rule to consider the exact knowledge of human operator. The fuzzy expert system is implemented with G2 which is an on-line expert system tool of Gensym Co. The application to a production furnace of Samsung-Corning Co. in Suwon shows successful results of proposed fuzzy expert system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.7
• /
• pp.1354-1362
• /
• 2015

Heterogeneous network technology is expected to be a core technology for 5G mobile communications. 5G mobile network would be composed of many base stations even have mobility, then the operator should connect base stations through the wireless backhaul technology. This paper presents Ultra Wide Area Wireless Backhaul Network System with massive array antenna. We conducted link budget analysis for Ultra Wide Area Wireless Backhaul Network and performance analysis of massive array antenna system through the transmission simulator based on beamforming technology. In wide area ($10km^2$) wireless backhaul system composed of massive antenna, we achieved 5 bps/Hz average spectral efficiency with 1 W transmission power per beam.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.1
• /
• pp.38-47
• /
• 2016

Objectives: The objective of this study was to determine the exposure levels of forklift operators to diesel engine exhaust(DEE) using black carbon(BC), elemental carbon(EC), and nitrogen dioxide($NO_2$) as indicators. Methods: A total of eight forklift operators in six collection companies were assessed over a period of two months from July to September 2015. BC was measured using a real-time monitor and respirable EC samples were analyzed using the NIOSH method 5040. $NO_2$ samples were collected using a passive badge-type sampler. Results: The geometric mean of BC, EC and $NO_2$ were $3.1-19.1{\mu}g/m^3$, $2.1-23.8{\mu}g/m^3$, and 12.5-166.6 ppb at all companies. When forklifts were operating both outside and inside, BC concentrations increased 2.0-5.6 times. The highest increase was observed when forklifts were operating indoors. The increase in BC concentrations varied by company(company A: 2.0 times, B: 3.2 times, C: 5.6 times, D: 2.1 times, E: 5.1 times, F: 2.6 times). The geometric mean of BC, EC, and $NO_2$ for the forklift operators was $9.6{\mu}g/m^3$, $7.9{\mu}g/m^3$, and 48.9 ppb, respectively. The geometric mean of BC, EC, and $NO_2$ for manufacturing workers was $9.3{\mu}g/m^3$, $0.9{\mu}g/m^3$, and 85.2 ppb, respectively. The mean BC and EC exposure levels for the forklift operators were slightly higher than those for manufacturing workers, but $NO_2$ levels for manufacturing workers were higher than those for the forklift operators(p>0.05). Multiple regression analysis revealed that diesel exhaust emissions standard, forklift weight and forklift manufacturer were the most influential factors in determining worker exposure. Conclusions: In the DEE work environment, workers who perform tasks within the workplace as well as inside forklifts as operators are likely to be exposed to a lack of ventilation. Further study of forklift operators' exposure to DEE indicators should be conducted to include a wider range of occupational and environmental situations, such as collection procedures, seasonal situations, types of fuel used, and number of forklifts.

• Journal of the Korean Mathematical Society
• /
• v.32 no.1
• /
• pp.17-31
• /
• 1995

A Lorentzian para-Sasakian manifold M$(\varphi, \zeta, \eta, g)$ (abr. LPS-manifold) has been defined and studied in [9] and [10]. On the other hand, para-Sasakian (abr. PS)-manifolds are special semi-cosympletic manifolds (in the sense of [2]), that is, they are endowed with an almost cosympletic 2-form $\Omega$ such that $d^{2\eta}\Omega = \psi(d^\omega$ denotes the cohomological operator [6]), where the 3-form $\psi$ is the associated Lefebvre form of $\Omega$ ([8]). If $\eta$ is exact, $\psi$ is a $d^{2\eta}$-exact form, the manifold M is called an exact Ps-manifold. Clearly, any LPS-manifold is endowed with a semi-cosymplectic structure (abr. SC-structure).