• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.1981-1987
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• 2001

This paper documents the effect of surface treatment of aluminum on the bonding strength of aluminum/CFRP composites. The surface of aluminum panel was treated by DC plasma. The optimal treatment condition of the aluminum was determined by measuring the contact angle and T-peel strength as functions of mixture ratio of acetylene gas to nitrogen gas. The mixture ratios used were 1:9, 3:7, 5:5, 7:3, and 9:1 Lap shear tests and T-peel tests were performed using surface-treated alumiunm/CFRP composites and regular alumiunm/CFRP composites. The results showed that the contact angle was minimized and the T-peel strength was maximized iota the mixture ratio of 5:5. The results also showed that the shear strength of surface-treated alumiunm/CFRP composites was 34% greater than that of regular alumiunm/CFRP composites. The T-peel strength of surface-treated alumiunm/CFRP composites was also 5 times greater than that of regular alumiunm/CFRP composites.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.12
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• pp.1715-1725
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• 1998

A two-dimensional transient inverse heat conduction problem involving the estimation of the unknown location, ($X^*$, $Y^*$), and timewise varying unknown strength, $G({\tau})$, of a line heat source embedded inside a rectangular bar with insulated boundaries has been solved simultaneously. The regular conjugate gradient method, RCGM and the modified conjugate gradient method, MCGM with adjoint equation, are used alternately to estimate the unknown strength $G({\tau})$ of the source term, while the parameter estimation approach is used to estimate the unknown location ($X^*$, $Y^*$) of the line heat source. The alternate use of the regular and the modified conjugate gradient methods alleviates the convergence difficulties encountered at the initial and final times (i.e ${\tau}=0$ and ${\tau}={\tau}_f$), hence stabilizes the computation and fastens the convergence of the solution. In order to examine the effectiveness of this approach under severe test conditions, the unknown strength $G({\tau})$ is chosen in the form of rectangular, triangular and sinusoidal functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4493-4501
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• 2011

This study was performed to determine the levels of MMSE-K among the elderly people affiliated with long-term care insurance services in rural areas, and to reveal its association with related variables. The interviews were performed, during the period from March 1st, to May 31th, 2009, to 410 elderlies in rural areas. As a results, The prevalence of cognitive functions among all subjects were 80.5% of severe cognitive impairment, 11.7% of mild cognitive impairment, and 7.8% of normal. The prevalence of cognitive functions were lower according to the higher grade of long-term care insurance. And the prevalence of cognitive functions were lower in the group of lower educational level, unemployed, live alone, lower monthly income, bear for living expenses by sons and daughters and medical aid, lower visual acuity, with urinary incontinence, with amnesia, without regular exercise and lower frequency of going out than their respective counterparts. The hierarchial multiple regression analysis was used to reveal the explanatory powers of factors influencing on the cognitive functions level. Such factors as age, bear for living expenses, visual acuity, urinary incontinence, amnesia, regular exercise and grade of long-term care services were significantly influenced with cognitive functions. especially the factors of health status were significantly influenced with cognitive functions.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.4
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• pp.296-302
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• 2010

This paper considers fuzzifying topologies, a special case of I-fuzzy topologies (bifuzzy topologies) introduced by Ying [16, (I)]. It investigates topological notions defined by means of regular open sets when these are planted into the frame-work of Ying's fuzzifying topological spaces (in ${\L}$ukasiewwicz fuzzy logic). The concept of fuzzifying nearly compact spaces is introduced and some of its properties are obtained. We use the finite intersection property to give a characterization of fuzzifying nearly compact spaces. Furthermore, we study the image of fuzzifying nearly compact spaces under fuzzifying completely continuous functions, fuzzifying almost continuity and fuzzifying R-map.

• Honam Mathematical Journal
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• v.41 no.4
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• pp.725-744
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• 2019

In this paper we introduce some new types of double difference sequence spaces defined by a new definition of convergence of double sequences and a double series with the help of sequence of Orlicz functions and a four dimensional bounded regular matrices A = (a_rtkl). We also make an effort to study some topological properties and inclusion relations between these sequence spaces. Finally, we compute the closed ideals in the space 𝑙²_∞.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1732-1750
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• 2010

Operation of KORAIL's level crossing is in charge of KORAIL. As taking over existing level crossing to KORAIL, they do not conduct risk assessments, so we do not know about any possibilities of inner risk. And present operation of safety of the level crossing is just regular checking of reaction and functions of safety equipments physically, we need to react to the changes of what's going on around of level crossing and incestigation of traffic flow and surrounding conditions more spontaneously. So, we have to prepare the strategies against accidents of level crossing cost-effectively based on regular risk assessments for sustainable safety improvements and overcome operational problems of present level crossing's safety. Here, we're going to investigate the level of safety level and present risk factors of the level crossing using risk assessments for accidents/error of the equipments to show operational strategies of level crossing based on risk assessments.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.298-304
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• 2003

In this paper a free-form hull design program and performance prediction program for planing boat is introduced. This program enables the designer to do complex geometric hull shape design on a personal computer and accurately to predict power requirements for a given loading and velocity. For a free form design, Bezier curve model is adopted as a basic representation tool of curves and surfaces, and this program has versatile functions to do fairing jobs with a convenient graphical user interface. After creating a hull form the geometric data is provided in a manner compatible with a variety of analysis tools including 'Motion Analysis(by Zarnick)' for prediction of motion characteristics in regular waves, 'Running Attitude (by Savitsky)' for prediction of the running attitude and required power.

• Proceedings of the Korean Society for the Gifted Conference
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• 2002.05a
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• pp.9-30
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• 2002

A 4-year joint research project (1999-2003), entitled "The Development of Multiple Talents (DMT)", has been designed and carrying out under the sponsorship of the National Science Council, R.O.C. (Taiwan). A 3-dimension construct is proposed for the DMT: form of talents (10 forms, mainly based on Gardner′s theory of multiple intelligences), function of talents (3 functions, based on Stemberg′s conception of successful intelligence), and developmental stage (4 stages, from pre-school to senior high). To take an example of its empirical studies, Wu and Chien (2000), based on a renovated conception of personal intelligence, developed the "Personal Intelligence Inventory" (PII). By means of the PII, it was found that there were some personal intelligence differences between gifted and regular pupils: however, gifted group was not as superior as on academic performance to the regular one (Wu '||'&'||' Chien, 2000). It was also found that there were significant relationships between pupils′personal intelligence and school adjustment in both groups (Tsai '||'&'||' Wu, 2000).

• Journal of Gifted/Talented Education
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• v.12 no.2
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• pp.59-69
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• 2002

A 4-year joint research project(1999-2003), entitled "The Development of Multiple Talents(DMT)", has been designed and carrying out under the sponsorship of the National Science Council, R.O.C. (Taiwan). A 3-dimension construct is proposed for the DMT: form of talents (10 forms, mainly based on Gardner's theory of multiple intelligences), function of talents (3 functions, based on Sternberg's conception of successfulintelligence), and developmental stage (4 stages, from pre-school to senior high). To take an example of its empirical studies, Wu and Chien (2000), based on a renovated conception of personal intelligence, developed the "Personal Intelligence Inventory" (PII). By means of the PII, it was found that there were some personal intelligence differences between gifted and regular pupils; however, gifted group was not as superior as on academic performance to the regular one (Wu & Chien, 2000). It was also found that there were significant relationships between pupils' personal intelligence and school adjustment in both groups (Tsai & Wu, 2000).

• Steel and Composite Structures
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• v.32 no.5
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• pp.643-655
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• 2019

Perforation and cutouts of structures are compulsory in some modern applications such as in heat exchangers, nuclear power plants, filtration and microeletromicanical system (MEMS). This perforation complicates dynamic analyses of these structures. Thus, this work tends to introduce semi-analytical model capable of investigating the dynamic performance of perforated beam structure under free and forced conditions, for the first time. Closed forms for the equivalent geometrical and material characteristics of the regular square perforated beam regular square, are presented. The governing dynamical equation of motion is derived based on Euler-Bernoulli kinematic displacement. Closed forms for resonant frequencies, corresponding Eigen-mode functions and forced vibration time responses are derived. The proposed analytical procedure is proved and compared with both analytical and numerical analyses and good agreement is noticed. Parametric studies are conducted to illustrate effects of filling ratio and the number of holes on the free vibration characteristic, and forced vibration response of perforated beams. The obtained results are supportive in mechanical design of large devices and small systems (MEMS) based on perforated structure.