• 대한수학회보
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• 제44권1호
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• pp.173-176
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• 2007

The non-existence is proved of four-dimensional mod 2 semisimple representations of Gal ($\=\mathbb{Q}/\mathbb{Q}$) which are unramified outside 2.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.173.1-173.1
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• 2000

• Smart Structures and Systems
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• 제30권2호
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• pp.173-181
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• 2022

The current paper presents a technique to detect crack in non-uniform cantilever-type pipe beams, that have step changes in the properties of their cross sections, restrained by a translational and rotational spring with a tip mass at the free end. An equation for estimating the natural frequencies for the non-uniform beams is derived using the boundary and continuity conditions, and an equivalent bending stiffness for cracked beam is applied to calculate the natural frequencies of the cracked beam. An experimental study for a step-changed non-uniform cantilever-type pipe beam restrained by bolts with a tip mass is carried out to verify the proposed method. The translational and rotational spring constants are updated using the neural network technique to the results of the experiment for intact case in order to establish a baseline model for the subsequent crack detection. Then, several numerical simulations for the specimen are carried out using the derived equation for estimating the natural frequencies of the cracked beam to construct a set of training patterns of a neural network. The crack locations and sizes are identified using the trained neural network for the 5 damage cases. It is found that the crack locations and sizes are reasonably well estimated from a practical point of view. And it is considered that the usefulness of the proposed method for structural health monitoring of the step-changed non-uniform cantilever-type pipe beam-like structures elastically restrained in the ground and have a tip mass at the free end could be verified.

• Journal of Korean Biological Nursing Science
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• 제15권4호
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• pp.173-183
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• 2013

Purpose: The purpose of this study was to compare the stress level and HPA axis activity of an internet game addiction group and non-addiction group in adolescents. Methods: A cross-sectional comparative study was performed with 140 male high school students from 9 vocational high schools at W city. Data were collected from July to September, 2012, using a questionnaire for measuring internet game addiction and stress level, blood samples for serum ACTH, and cortisol level for HPA axis activity. Data were analyzed using descriptive analysis, $X^2$-test, t-test, ANOVA, and Pearson correlation coefficient with SPSS/WIN 15.0. Results: The stress level of the internet game addicted group was significantly higher than that of the non-addicted group (p<.001). The serum cortisol level was also significantly higher in the internet game addicted group than in the non-addicted group (p<.026). The serum ACTH level was higher in the internet game addicted group more than in the non-addicted group (p<.072). Conclusion: These results showed that internet game addiction could increase stress level and HPA axis activity in high school adolescents. Thus, a nursing approach to prevent and relieve internet game addiction should be initiated to stabilize the HPA axis of internet game addicted adolescents.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.159-173
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• 1998

Quality characteristics on the properties of process capability indices (PCIs) are often required to be normally distributed. But, if a characteristic is not normally distributed, serious errors can result from normal-based techniques. In this case, we may well consider the use of new PCIs specially designed to be robust for non-normality. In this paper, a newly proposed measure of process capability is introduced and compared with existing PCIs using the simulated non-normal data.

• 자연과학논문집
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• 제14권1호
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• pp.25-37
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• 2004

T7 RNA 중합효소는 두 종류의 인자 독립형 전사 종결신호를 인지하여 전사연장을 종결하게 되는데 이 중 머리핀 구조가 만들어지지 않는 PHT와 CJ 전사종결 부위는 ‘ATCTGTT' non-template 염기서열 다음에 T염기가 많은 부분이 존재하는 형태로 이루어져 잇다. 이와 같은 전사종결을 민감하게 인지하는 돌연변이 T7 RNA 중합효소인 X4, X19, BG8과 이와 반대로 둔감하게 인지하는 R173C를 제조하여 전사활성도를 측정하였다. 이결과 야생형 T7 RNA 중합효소에 비해 X4는 8%, X19는 33%, BG8은 34%의 전사활성도를 보여 전사활성도가 상당히 감소하는 결과를 보였다. 반면에 R173C는 야생형에 비해 112%의 전사활성도를 보여 야생형과 거의 유사한 전사활성도를 보였다. 또한 PTH 및 CJ 전사종결 부위를 전사주형으로 이용하여 전사하였을 때 X4, X19, BG8은 야생형 RNA중합효소에 비해 종결 부위에서의 종결이 증가하였으나 R173C는 거의 PTH 및 CJ 전사종결부위에서 전사종결이 일어나지 않고 전사가 진행되는 것을 확인하였다.

• 응용통계연구
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• 제6권1호
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• pp.173-181
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• 1993

각 성분 문제에서, 표본의 크기가 상이한 경우 Dirichlet process prior에 대한 경험적 베이 즈에 대한 분포함수의 추정문제를 연구하였다. 특히, 위의 경험적 베이즈 문제에 사용할 수 있도록 Zehnwirth의 $\alpha(R)$을 수정하였다.

• Applied Microscopy
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• 제43권4호
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• pp.173-176
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• 2013

The oxidation behavior of the crystallized $Al_{87}Ni_3Y_{10}$ alloy has been investigated with an aim to compare with that of the amorphous $Al_{87}Ni_3Y_{10}$ alloy. The oxidation at 873 K occurs as follows: (1) growth of an amorphous aluminum-yttrium oxide layer (~10 nm) after heating up to 873 K; and (2) formation of $YAlO_3$ crystalline oxide (~220 nm) after annealing for 30 hours at 873 K. Such an overall oxidation step indicates that the oxidation behavior in the crystallized $Al_{87}Ni_3Y_{10}$ alloy occurs in the same way as in the amorphous $Al_{87}Ni_3Y_{10}$ alloy. The simultaneous presence of aluminum and yttrium in the oxide layer significantly enhances the thermal stability of the amorphous structure in the oxide phase. Since the structure of aluminum-yttrium oxide is dense due to the large difference in ionic radius between aluminum and yttrium ions, the diffusion of oxygen ion through the amorphous oxide layer is limited thus stabilizing the amorphous structure of the oxide phase.

• Interaction and multiscale mechanics
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• 제3권2호
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• pp.173-191
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• 2010

Damage detection plays a very important role to the maintenance of bridge structures. Traditional damage detection methods are usually based on structural dynamic properties, which are acquired from pre-installed sensors on the bridge. This is not only time-consuming and costly, but also suffers from poor sensitivity to damage if only natural frequencies and mode shapes are concerned in a noisy environment. Recently, the idea of using the dynamic responses of a passing vehicle shows a convenient and economical way for damage detection of bridge structures. Inspired by this new idea and the well-established tap test in the field of non-destructive testing, this paper proposes a new method for obtaining the damage information through the acceleration of a passing vehicle enhanced by a tapping device. Since no finger-print is required of the intact structure, this method can be easily implemented in practice. The logistics of this method is illustrated by a vehicle-bridge interaction model, along with the sensitivity analysis presented in detail. The validity of the method is proved by some numerical examples, and remarks are given concerning the potential implementation of the method as well as the directions for future research.

• Steel and Composite Structures
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• 제31권2호
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• pp.173-185
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• 2019

This paper presents experimental and numerical investigations of aluminum tubular members subjected to combined bending and web crippling. A series of tests was performed on square hollow sections (SHS) fabricated by extrusion using 6061-T6 heat-treated aluminum alloy. Different specimen lengths were tested to obtain the interaction relationship between moment and concentrated load. The non-linear finite element models were developed and verified against the experimental results obtained in this study and test data from existing literature for aluminum tubular sections subjected to pure bending, pure web crippling, and combined bending and web crippling. Geometric and material non-linearities were included in the finite element models. The finite element models closely predicted the strengths and failure modes of the tested specimens. Hence, the models were used for an extensive parametric study of cross-section geometries, and the web slenderness values ranged from 6.0 to 86.2. The combined bending and web crippling test results and strengths predicted from the finite element analysis were compared with the design strengths obtained using the current American Specification, Australian/New Zealand Standard and European Code for aluminum structures. The findings suggest that the current specifications are either quite conservative or unconservative for aluminum square hollow sections subjected to combined bending and web crippling. Hence, a bending and web crippling interaction equation for aluminum square hollow section specimens is proposed in this paper.