• 한국정밀공학회지
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• 제17권3호
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• pp.192-199
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• 2000

The spot-welded automotive side member which has a hat-shaped section and a double hat shaped section has been tested on the axial static(10mm/min) and quasi-static(50mm/min) compressing load. The collapse characteristics of automotive sections have been reviews on shift on shape and in width of the spot-voiding on the flange. On the basis of the results of tests and reviews, the optimum energy absorption capacity of the structure has been studied.

• Journal of Mechanical Science and Technology
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• 제15권2호
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• pp.180-191
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• 2001

The widely used spot welded sections of automobiles(hat and double hat shaped section members) absorb most of the energy in a front-end collision. The sections were tested with respect to axial static(10mm/min) and quasi-static(1000mm/min) loads. Based on these test results, specimens with various thicknesses, width ratios and spot weld pitches on the flange were tested at high impact velocity(7.19m/sec and 7.94m/sec) which simulates an actual car crash. Characteristics of collapse have been reviewed and structures for optimal energy absorbing capacity is suggested.

• 한국정밀공학회지
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• 제17권5호
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• pp.195-201
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• 2000

The fundamental spot welded sections of automobiles (hat-shaped and double hat-shaped sections) absorb most of the energy in a front impact collision. The sections of various thickness, shape and weld width on the flange lave been tested on axial impact crush load (Mass 40kg, Velocity 7.19m/sec) using a vertical air pressure crash est device Characteristics of impact collapse have been reviewed and a structure of optimal energy absorbing capacity is suggested.

• 한국해양공학회지
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• 제16권1호
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• pp.58-63
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• 2002

In this research, a design guideline of current generating HAT rotor and acceptable field rotor in offshore environment is proposed. To design HAT rotor model, wind mill rotor design principles and turbine theories were applied based on a field HAT rotor experimental data. To verify the compatibility of the rotor design method and to analyze the properties of design factors, 3 rotor models were designed and experimented in a circular water channel. Three rotor models were designed according to different blade numbers and blade shapes. By changing flow velocity, rotor rpm, the rotor power and efficiency were measured and the properties of rotor were estimated. The results can be effectively applied to the design of current generation rotor.

• 한국안전학회지
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• 제15권4호
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• pp.20-27
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• 2000

The hat shaped section members, spot welded strength resisting structures are the most energy absorbing ones of automobile components during the front-end collision. Under the static axial collapse load in velocity of 10mm/min and quasi-static collapse load in velocity of 1000mm/min, the collapse characteristics of the hat shaped section and double hat shaped section member have been analyzed by axial collapse tests with respect to the variations of spot weld pitches on the flanges. In addition, the quasi-static collapse simulations have been implemented in the same condition to the experiment's using FEM package, LS-DYNA3D. The simulated results have been verified in comparison with these from the quasi-static axial collapse tests. With the computational approaches the optimal energy absorbing structures can be suggested. Simulations are so helpful that the optimized data be supplied in designing vehicles in advance.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 추계 학술발표회 논문집
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• pp.55-58
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• 2005

This paper discusses the asymptotic efficiency of estimators for optimal portfolios when returns are vector-valued non-Gaussian stationary processes. We give the asymptotic distribution of portfolio estimators ${\hat{g}}$ for non-Gaussian dependent return processes. Next we address the problem of asymptotic efficiency for the class of estimators ${\hat{g}}$ First, it is shown that there are some cases when the asymptotic variance of ${\hat{g}}$ under non-Gaussianity can be smaller than that under Gaussianity. The result shows that non-Gaussianity of X(t) does not always affect worse. Second, we give a necessary and sufficient condition for ${\hat{g}}$ to be asymptotically efficient when the return process is Gaussian, which shows that ${\hat{g}}$ is not asymptotically efficient generally. From this point of view we propose to use maximum likelihood type estimators for g, which are asymptotically efficient. We examine our approach numerically.

• 복식문화연구
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• 제3권1호
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• pp.1-15
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• 1995

This study is concerned with the julpoong of Koguryo. The meaning, form, structure, user, the origin of the word the julpoong were examined. The pien of he ancient China and the julpoong of Koguryo were examined. The result of the analysis of this study is as follows. The Chinese and the people of Koguryo used the meanings of the julpoong differently : the Chinese referred the julpoong to the conical hat with the seams including one seam on it, while the people of Koguryo called the julpoong as the conical hat with seams excluding one seam on it. the people of Koguryo called the julpoong with one seam as the chack . The julpoong was used by all people of Koguryo : the government officials, envoys, and the commoners wore it. The word julpoong of Koguryo was derived from dulband, dulband, dubend, dolband of Persians. the word julpoong is correspondent with the above the persian words. The julpoong of Koguryo word was transliteration of dulband(dulband, dulbend, dolband) meaning turban or sash. The hat called chack by the people of 고구려 was the conical hat with one sea and their meaning of he chack was different from the meaning of the chack of the Chinese. The julpoong a kind of conical hat, was called by the pine by the ancient Chinese.

• 충청수학회지
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• 제21권2호
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• pp.269-278
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• 2008

Let ${\partial}D$ be the boundary of the open unit disk D in the complex plane and $L^p({\partial}D)$ the class of all complex, Lebesgue measurable function f for which $\{\frac{1}{2\pi}{\int}_{-\pi}^{\pi}{\mid}f(\theta){\mid}^pd\theta\}^{1/p}<{\infty}$. Let P be the orthogonal projection from $L^p({\partial}D)$ onto ${\cap}_{n<0}$ ker $a_n$. For $f{\in}L^1({\partial}D)$, ${\hat{f}}(z)=\frac{1}{2\pi}{\int}_{-\pi}^{\pi}P_r(t-\theta)f(\theta)d{\theta}$ is the harmonic extension of f. Let ${\hat{P}}$ be the composition of P with the harmonic extension. In this paper, we will show that if $1, then ${\hat{P}}:L^p({\partial}D){\rightarrow}H^p(D)$ is bounded. In particular, we will show that ${\hat{P}}$ is unbounded on $L^{\infty}({\partial}D)$.

• 한국의류산업학회지
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• 제12권3호
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• pp.372-380
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• 2010

The purpose of this study were to investigate a preference and demand performance of UV protective hat for outdoor sports activities. Data collected from 259 adults from survey were analyzed by frequence analysis, crosstabs, t-test, and ANOVA using SPSS 17.0. The results are as follows. A demand performanc of UV protective hats were a demand performance for designs, colors, fabrics, lightness, UV protection, and easy care. It showed that the respondents worn the hats for skin health and didn't wear for sun block. The demand performance of UV protective hat showed difference according to gender and age. The favorite type of UV protective hat was cap, and there was no difference between young and old age. Male preferred the cap styles, while female preferred the wide brim styles for UV protection. The preferred fiber contents of the respondents were cotton and functional fiber.

• 복식문화연구
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• 제4권2호
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• pp.207-217
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• 1996

The founding of ching costume system starts from the rule issued in second year of Te-chong reign that the clothing of Manchu people is prohibited to be chinesized. It has undergone many revisions and is officially established in the 37th year of Chien-lung reign. This study is Emperor's costumes during the year in Chien-lung reign. The results are as follows: Emperor's costumes go to the travel are Chi-fu hat and Hsing-fu. Sea-dragon hat changes on otter skin or beaver hat and Ching-rong and ching-ni hat changes velvet hat. Light green informal wear is to be worn once a year. Name of sacrificial robes does not exist in Ching-hui-dien-tu but it take the place of Chao-fu I and Chao-dai II in Chuan-dai-dang-an. Sacrificial robes wear with indigo boots and the other cases wear blue boots and shoes and socks. The shape on ornaments in belt of sacrificial robes is tetragon style.