• Structural Engineering and Mechanics
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• 제2권3호
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• pp.295-309
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• 1994

The present paper concerns the mathematical study and the numerical treatment of the problem of semirigid connections in bolted steel column base plates by taking into account the possibility of appearance of separation phenomena on the contact surface under certain loading conditions. In order to obtain a convenient discrete form to simulate the structural behaviour of a steel column base plate, the continuous contact problem is first formulated as a variational inequality problem or, equivalently, as a quadratic programming problem. By applying an appropriate finite element scheme, the discrete problem is formulated as a quadratic optimization problem which expresses, from the standpoint of Mechanics, the principle of minimum potential energy of the semirigid connection at the state of equilibrium. For the numerical treatment of this problem, two effective and easy-to-use solution strategies based on quadratic optimization algorithms are proposed. This technique is illustrated by means of a numerical application.

• Wind and Structures
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• 제6권5호
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• pp.347-356
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• 2003

Experimental studies on drag reduction of a circular cylinder of diameter D were conducted in the subcritical flow regime at Reynolds numbers in the range $4{\times}10^4{\leq}Re{\leq}10^5$. To shield the cylinder rear surface from the pressure deficit of the unsteady vortex generation in the near wake, two shield plates were attached downstream of the separation points to form a cavity at the base region. The chord of the shield plates, L, ranged from 0.22 to 1.52 D and the cavity width, G, was in the range from 0 to 0.96 D. It is concluded that significant drag reductions from that of a plain cylinder may be achieved by proper sizing of the shield plates and the base cavity. The study shows that using a pair of shield plates at G/D of 0.86 and angular position ${\theta}$ of ${\pm}121^{\circ}$ results in a configuration with percentage drag reduction of 40% for L/D of 0.5, and 55% for L/D of 1.0.

• Tribology and Lubricants
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• 제17권3호
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• pp.171-178
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• 2001

In order to elucidate the lubricating mechanism of polyolester base oils [POEs], the wear characteristics of 27 kinds of polyolester base oils including mixed POEs were investigated. Their wear results were discussed in terms of the effect of molecular structure on wear performance and compared with those of mineral oil. In addition, the adsorption ability of POEs to reduced iron and their hydrolysis rates were measured and the effect of their molecular structures on the adsorptivity and hydrolysis rate of POEs was discussed, respectively. Finally, the lubricating mechanism anlyzed from these results of wear characteristics, adsorptivity and hydrolysis rate was proposed. That is to say, POEs are firstly adsorbed to friction surface and decomposed by hydrolysis or thermal degradation. Fatty acids obtained by degradation of POEs form adsorption film on friction surface. The larger become cohesive ability among fatty acid molecules in the adsorption film, the better gets the wear performance of POEs.

• 복식
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• 제36권
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• pp.139-148
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• 1998

In order to know what sorts of features of neck form may be required to make plans for tight collars, the neck form of young japanese women were measured three demension-ally using GRASP(Grating Projection System for Profiling) and plaster torso. By the BASIC language in NEC computer and EXCEL program in MACINTOSHI computer, it became possible to draft a number of neck surface auomatically, therefore, we got analysis of a mass of subjects. Thed following results were obtained: 1. There was a large individual difference in the shape of neck, in particular, on the front and side curves of the neck base line, where the undulation of clavicular part of neck and inclination of shoulder are refracted. 2. When designing a stand collar, from the viewpoint of clothing strcture, it is important to grasp exactly the shapes of the neck, such as the line of the neck base, the neck gradient, back neck length, back neck width & girth. 3. According to the somatotypes(turing-over, standard, bending type), there were different the method of the basic collar pattern making.

• 경영과학
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• 제12권1호
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• pp.19-34
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• 1995

The objective of this paper is to present a framework for an expert system for fault diagnosis in an FMS (Flexible Manufacturing Systyem). First, a system is analyzed structurally and functionally, giving the relationships between the system's components. These relationships, represented by strata, are are then stored in a deep knowledge base (DKB). Next, the specific knowledge, represented by echelons, about the symptoms and their probable causes for each component is stored in a shallow knowledge base (SKB) in the form of rule. When the fault diagnosis process begins, it starts to search the DKB and then the SKB, which is called hybrid reasoning in artificial intelligence.

• 약학회지
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• 제26권3호
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• pp.175-180
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• 1982

The intermediate of N'-nitrosonornicotine may bind to the guanine moiety of a G-C base pair. The hydrogen bond of the base pair may be broken and a new hydrogen bond can form between the intermediate and the guanine. It results in the "short" type of DNA repair.NA repair.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.374-379
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• 1988

We propose a framework for modelling and operation management of robotic assembly cells via knowledge base. In the framework, each component of the cell is considered as a state variable, the relations among the state variables are stored in state transition maps(STMs) and then transformed into the form of knowledge. The assembly job tree(AJT) which includes the precedence relations and the constraints for assembly tasks is also described. Finally, an algorithm is presented to manage the cell operation.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.93-101
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• 1984

The experimental study was made to investigate the effect of the "Heliosit" composite resin on the dental pulp. The 36 class V cavities were prepared on the healthy permanent teeth of 3 days, and were divided into 5 groups and filled with the experimental filling materials. Control group: Zinc Oxide-Eugenol cement filling Experimental groups: Group 1: Dentin Adhesit application & Heliosit filling with or without dycal base Group 2: Heliosit filling with or without dycal base Group 3: Durafill filling with dycal base Group 4: Hipol filling with dycal base Animals were sacrificed after 1 weeks, 2 weeks, and 4 weeks following operation. The teeth were decalcified, sectioned and stained with hematoxylin and eosin. The results obtained form this study were as follows: 1. All experimental group showed slight pulp response. 2. Dentin Adhesit group showed minimal pulp response in both dycal bases and no base cases. 3. In group 2, mild pulp response was found in early stage and repairing process was found as the time elapsed. In no base cases, healing process was delayed slightly. 4. There was little difference in the result among Heliosit group, Durafill group and Hipol group.

• Smart Structures and Systems
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• 제9권2호
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• pp.165-188
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• 2012

In the first part of the paper, the optimal design parameters for tuned liquid column dampers (TLCD) in harmonic pitching motion were investigated. The configurations in design tables include uniform and non-uniform TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 for the design in different situations. A closed-form solution of the structural response was used for performing numerical optimization. The results from optimization indicate that the optimal structural response always occurs when the two resonant peaks along the frequency axis are equal. The optimal frequency tuning ratio, optimal head loss coefficient, the corresponding response and other useful quantities are constructed in design tables as a guideline for practitioners. As the value of the head loss coefficient is only available through experiments, in the second part of the paper, the prediction of head loss coefficients in the form of a design chart are proposed based on a series of large scale tests in pitching base motions, aiming to ease the predicament of lacking the information of head loss for those who wishes to make designs without going through experimentation. A large extent of TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 and orifice blocking ratios ranging from 0%, 20%, 40%, 60% to 80% were inspected by means of a closed-form solution under harmonic base motion for identification. For the convenience of practical use, the corresponding empirical formulas for predicting head loss coefficients of TLCDs in relation to the cross-sectional ratio and the orifice blocking ratio were also proposed. For supplemental information to horizontal base motion, the relation of head loss values versus blocking ratios and the corresponding empirical formulas were also presented in the end.

• 한국생활과학회지
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• 제16권5호
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• pp.969-977
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• 2007

The research thesis has been intended to make a comparative analysis on the basic bodice pattern and basic skirt pattern changing on the basis of setting waist line of dress form in an effort to set reasonable standards in selecting the standard lines of drees form. The thesis has made the wearing evaluation by producing the sample of upper and lower dress based on A pattern and B pattern. In details, A pattern functions to keep waist line flatly down from lateral waist-right to posterior waist in a little curved state, paralleling bust line and hipline with waistline. And, B pattern functions to keep waistline, bust line and hipline horizontal paralleling with ground surface. SPSS win 10.1 program was used for the analysis of evaluation and t-test. The result is as follows: For basic bodice-front of upper dress, A and B patterns have made little significant difference. With regard to basic bodice-back, B pattern has got the higher evaluation than A pattern, in the pattern stability and appearance. For basic skirt pattern, A pattern has got the lower evaluation in the aspect of total back appearance, back dart, hip line, and waist line, and front drape. Basic bodice pattern of A pattern, which takes on the different horizontal standard lines of dress form depending on the selection of waistline, and basic skirt pattern has scored less in terms of pattern stability and appearance.