• Steel and Composite Structures
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• 제43권3호
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• pp.363-373
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• 2022

As a key reinforcement connection between a tower and a substructure in offshore wind turbine system, the transition piece is inevitably subjected to cyclic dynamic environmental loads such as wind, current and wave. Therefore, well designed transition piece with high strength and good fatigue resistance is of great significance to the structural safety and reliability of offshore wind power systems. In this study, the structural behavior of the transition piece was studied by an extensive sets of finite element analyses. Three widely used types of transition piece were considered. The characteristics of stress development, fatigue life and weight depending on the type of the transition piece were investigated in the ultimate limit state (ULS) and the fatigue limit state (FLS) of a 5-MW offshore wind turbine to be placed in Korea. An optimal form of the transition piece was proposed based on this parametric study.

• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.160-168
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• 2020

Depending on the water depth and composition of seabed, there exist different alternatives for the wind turbine supporting structures. Among several types of the structures, the monopile foundation is the dominant solution for support structure, accounting for over 80% of the offshore wind turbines in Europe. To develop the monopile foundation suitable for domestic ocean environment, a basic design of a transition piece was carried out. This paper presents the design procedure of a flange connected transition piece and results of the structural safety assessment.

• 한국안전학회지
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• 제8권4호
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• pp.107-113
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• 1993

Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

• 복식
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• 제53권4호
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• pp.71-85
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• 2003

The costume of the 17th Century based on the excavated costume from the graves of Tong-Rae Jwg Clan are studied in this paper. The remaining were used for filling up the coffin consists of 1 piece of Dopo(도포) from the grave of Jung, Kwang-Kyung, 7 pieces of Joongchimak(중적막), 1 piece of Sochng-eui(소창의), and 1 piece of pants from the grave of Jae-Hoo Jung, grand-son of Kwang-Kyung Jung. From these remainings, this study newly reveals or confirms : 1) Standards of transition Procedure of mid-l7th century's Dopo with gussets, 2) Standards of transition procedure of late 17th century's Joongchimak with wide sleeves and side slits, 3) Standards of transition procedure of late 17th century's Sochang-eui with narrow sleeves and side slits, 4) Typical style of pants in the 17th century, 5) The constructive methods for quilted fabric.

• 대한가정학회지
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• 제35권1호
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• pp.401-414
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• 1997

This study examined the transition of costume in middle and high school girls after the abolition of school-uniform. Fashion photographs of $\ulcorner$Junior$\lrcorner$a Korean magazine for girls were used for the investigation. Skirts used mainly were changed in order of pleat tight flare and tight skirt And skirt length was changed in order of knee midi knee and mini. Slim baggy and straight pants together showed high frequency but after 1992 straight pants were used mainly. And pants of ankle length was prevalent. In jacket Hip line natural waist and H-line silhouette dominated. Silhouette of one-piece dress was changed in order or X line H line and A line. Semi fit and natural waist were prevalent. And length was changed in order of midi knee and mini. The coat of H line Loose semi fit and Knee length was the most frequently appeared style. Waist line of coat was changed in order of natural low no natural waist. In skirt blue white black and black were mainly in spring summer fall and winter respectively. In pants blue was used mainly regardless of the season, In jacket blue in spring and black in other seasons were used. In one-piece derss blue in spring red in summer black in fall and winter were used mainly. Black coat was used mainly. Therefore blue was the most frequently used color by middle and high school girls.

• 고전문학과교육
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• 제15호
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• pp.303-327
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• 2008

The purpose of this paper is the analysis of to point its structure and meaning deduced from the rite of passage. In the light of the rite of passage, could be retrieved its value as one of significant works among the works of Gangho-sijo. is composed of nineteen pieces of monotype sijo. The first piece is a kind of prologue. The other pieces are divided into three parts which correspond with the three stages of the rite of passage-separation, transition, incorporation. As a result of this analysis, we can find out the writer's cognitive change according to the schema of the rite of passage. It becomes clear that the space of Gangho means the sacred space for mental culture rather than a separate space for escape. And considering the withdrawal for Gangho as the transition process of the rite of passage, gives a description of the disentanglement of conflict and a incorporation into the superior position of spirit.

• Progress in Superconductivity
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• 제9권2호
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• pp.162-166
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• 2008

We are developing a sensitive gamma ray spectrometer based on superconducting transition edge sensors. The detector consists of a small piece of high purity Sn as an absorber and a Ti/Au bilayer as a temperature sensor. It is designed to measure the thermal signal caused by absorption of gamma rays. The mechanical support and the thermal contact between the absorber and the thermometer were made with Stycast epoxy. The bilayer was formed by e-beam evaporation and patterned by wet etching on top of a $SiN_X$ membrane. A sharp superconducting transition of the film was measured near 100 mK. When the film was biased to the edge of the transition, signals were observed due to single photon absorption emitted from an $^{241}Am$ source. The measured spectrum showed several characteristic peaks of the source including 59.5 keV gamma line. The full with at half maximum was about 900 eV for the 59.5 keV gamma line. The background was low enough to resolve low energy lines. Considerations to improve the energy resolution of the gamma ray spectrometer are also discussed.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 Proceedings of 6th International Joint Symposium on Microeletronics and Packaging
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• pp.27-34
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• 2001

The BGA Package has been the area array package of choice for several rears. Recently, the transition has been to finer pitch configuration called Chip Scale Packages (CSP). Several of these package types are available at 0.5 mm pitch, requiring surface mount assemblers to evaluate and optimize various elements of the assembly process. This presentation describes the issues associated with making the transition from BGA to CSP assembly. Areas addressed will include the accuracy of pick and piece equipment, printed wiring board lines and spaces, PWB vias, in-circuit test issues, solder paste printing, moisture related factors, rework and reliability. The transition to 0.5 mm pitch requires careful evaluation of the board design, solder paste selection, stencil design and component placement accuracy. At this pitch, ball and board pad diameters can be as small as 0.25 mm and 0.20 mm respectively. Drilled interstitial vias are no longer possible and higher ball count packages require micro-via board technology. The transition to CSP requires careful evaluation of these issues. Normal paste registration and BGA component tolerances can no longer achieve the required process levels and higher accuracy pick and place machines need to be implemented. This presentation will examine the optimization of these critical assembly operations, contrast the challenges at 0.5 mm and also look at the continuation of the process to incorporate smaller pitch flip chip devices.

• 대한가정학회지
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• 제35권3호
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• pp.307-318
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• 1997

I observed the important factors of clothing transition - Changes of Korean clothing & reception of Western-style dress - through the survey of the clothing of girl students during the period of enlightenment(1900∼1945) in this study as follows. 1) Stop to use of a long hood an old-fashioned woman shawI(once used to cover th head and upper body when going out). 2) Appearance of same colored Korean costume of the upper and lower sides. 3) Appearance of a short seamless one-piece skirt with a pair of shoulder girdles. 4) Appearance of school uniform, upper white lower black-Korean costume. 5) Appearance of school uniform, Western style. 6) Appearance of sports-wear. 7) Reformation of under-wear. 8) Appearance of short hair. 9) Appearance of socks & stockings and shoes.

• 소성∙가공
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• 제13권5호
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• pp.435-440
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• 2004

The temperature in hot forming of metallic materials, such as hot extrusion and hot forging, ranges from $300^{\circ}C$ to $900^{\circ}C$. Correspondingly, the die also exhibits high temperatures close to that of a work piece and its life is limited generally by high temperature fatigue. Thus, the analysis of high temperature fatigue would need the mechanical properties over the wide ranges of temperature. However, very few studies on the high temperature fatigue of brittle materials have been reported. Especially, the study on the fatigue behavior over such transition temperature regime is very rare. In this paper, the stress-strain curves and stress-life curves of a die steel such as STD61 are experimentally obtained. The wide ranges of temperature from $300^{\circ}C$ to $900^{\circ}C$ are considered in experiments and the transition temperature zone is carefully examined.