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Mechanical Characteristics and Macro-and Micro-structures on Friction Stir Welded Joints with 5083O Al Alloys (Al 5083O합금의 마찰교반용접부의 조직과 특성평가)

  • Jang, Seok-Ki;Park, Jong-Seek
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.1
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    • pp.104-111
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    • 2009
  • This paper shows the behaviors of macro- and micro-structures and mechanical properties for specimen's welding region welded by FSW. according to welding conditions with 5mm thickness aluminum 5083O alloy plate. It apparently results in defect-free weld zone in case traverse speed was changed to 32 mm/min under conditions of anti-clockwise direction and tool rotation speed such as 800 and 1250 rpm with tool's pin diameter of 5 ${\Phi}mm$ and shoulder diameter of 20 ${\Phi}mm$, pin length of 4.5 mm and tilting angle of $2^{\circ}$. The ultimate stress of ${\sigma}_T=331$ MPa and the yield point of 147 MPa are obtained at the condition of the travel speed of 32 mm/min with the tool rotation speed of 1250 rpm. There is neither voids nor cracks on bended surface of $180^{\circ}$ after bending test. The improvement of toughness after impact test was found. The lower rotating and traverse speed became, the higher were yield point, maximum stress and elongation(%) with the stresses and the elongation(%) versus the traverse speed diagram. Vickers hardness for cross section of welding zone were also presented. The typical macro-structures such as dynamically recrystallized zone, thermo-mechanically affected zone and heat affected zone and the micro-structures of the transverse cross-section were also showed. However, the author found out that the region of 6mm far away from shoulder circumference was affected by friction heat comprehensively, that is, hardness softened and that part of micro-structures were re-solid-solution or recrystallized, the author also knew that there is no mechanically deformation on heat affected zone but there are the flow of plastic deformation of $45^{\circ}$ direction on thermo-mechanically affected zone and the segregation of Al-Mg on nugget. The solid solution wt(%) of parent material as compared against of friction stir welded zone was comprehensively changed.

Semiotic Interpretation of Vivienne Westwood's Works Reflected Punk Rock (펑크록이 반영된 Vivienne Westwood 작품의 기호적 해석)

  • 장애란
    • Journal of the Korean Society of Costume
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    • v.39
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    • pp.197-215
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    • 1998
  • Vivienne Westwood, the revolutionary cre-ator of Punk fashion(ripped T-shirts, bondage clothes, fetishist accoutrements) was a street fashion designer. Although Westwood's clothes have frequently been described as decadent, degenerate and unwearable, they have also exerted a powerful influence on interntional fashion. Westwood became a fashion designer in the mid-1970s, when he emergence of Punk put London back on the fashion map for the first time since 1965. Just as the Mods, Rockers, and Hippies of the 1960s had embraced par-ticular styles of dress and music, so also did the Punks create their own subculture. The Punk“style in revolt”was a deliberately“re-volting style”that incorporated into fashion various offensive or threatening objects like tampons, razor blades, and lavatory chains. Vivienne Westwood and parter Malcolm McLaren articulated this youth culture, who roots lay in music. A sign is something which stands for some object or idea, while the semiotics are the ex-ternal expression for an internal meaning. Semiotics can be used as a medium of communication between dress and music. A language is simply used for explicit of meaning, while the style of dress and music express the explicative and implicative signs. Peirce's scheme among several theories of the semiotics was chosen for this study, because the Peirce's scheme was the first non-language communication medium between external and internal stages, and readily inter-preted the styles of dress and music. Punk rock was studied at first to identify the style which influenced Vivienne Westwood's works and then Semiotics were used to apply the above results to the 1970s and 1990s for analyzing and interpreting the Vivienne Westwood's works were also interpreted by the symbolic characteristics of Semiotics, because the symbol of semiotics often found at Youth Cults reflected punk rock. The symbol of revolt, decadence, grungy, freedom in Vivienne Wes-twood's works wre determined by using Punk rock's semiotics. This study could conclude that the style of dress and punk rock were able to be interpreted by semiotics.

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Large-Eddy Simulation of Turbulent Channel Flow using a Viscous Numerical Wave Tank Simulation Technique (점성 수치파랑수조 구축을 위한 LES 기술의 평판간 난류유동에의 적용)

  • Park, Jong-Chun;Kang, Dae-Hwan;Kim, Bang-Eun;Yoon, Hyeon-Sik;Chun, Ho-Hwan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.204-212
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    • 2003
  • As the first step to investigate the nonlinear interactions between turbulence and marine structures inside a viscous NWT, a LES technique was applied to the turbulent channel flow for $Re_{T}=150$, in this paper. The employed models were 4 types, such as the Smagorinsky model, the Dynamic SGS model, the Structure Function model and the Generalized Normal Stress model. The simulated data in time-series for the LESs were averaged in both time and space and performed statistical analysis. And results of the LESs were compared with those of a DNS developed in the present study and two spectral methods by Yoon et al.(2003) & Kim et al.(1987). It seems to be quite difficult to evaluate their performances to the present problem, but is seen that the accuracy of LESs are still related to the number of grids(or fine grid size).

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A 900 MHz Zero-IF RF Transceiver for IEEE 802.15.4g SUN OFDM Systems

  • Kim, Changwan;Lee, Seungsik;Choi, Sangsung
    • ETRI Journal
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    • v.36 no.3
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    • pp.352-360
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    • 2014
  • This paper presents a 900 MHz zero-IF RF transceiver for IEEE 802.15.4g Smart Utility Networks OFDM systems. The proposed RF transceiver comprises an RF front end, a Tx baseband analog circuit, an Rx baseband analog circuit, and a ${\Delta}{\Sigma}$ fractional-N frequency synthesizer. In the RF front end, re-use of a matching network reduces the chip size of the RF transceiver. Since a T/Rx switch is implemented only at the input of the low noise amplifier, the driver amplifier can deliver its output power to an antenna without any signal loss; thus, leading to a low dc power consumption. The proposed current-driven passive mixer in Rx and voltage-mode passive mixer in Tx can mitigate the IQ crosstalk problem, while maintaining 50% duty-cycle in local oscillator clocks. The overall Rx-baseband circuits can provide a voltage gain of 70 dB with a 1 dB gain control step. The proposed RF transceiver is implemented in a $0.18{\mu}$ CMOS technology and consumes 37 mA in Tx mode and 38 mA in Rx mode from a 1.8 V supply voltage. The fabricated chip shows a Tx average power of -2 dBm, a sensitivity level of -103 dBm at 100 Kbps with PER < 1%, an Rx input $P_{1dB}$ of -11 dBm, and an Rx input IP3 of -2.3 dBm.

Effects of the Life Review-Narrative Group Therapy Program on Decreasing Depression and Death Anxiety in the Elderly (노년기 우울과 죽음불안 감소를 위한 생애회고적 이야기치료 집단프로그램의 효과)

  • Yeo, In-Suk;Kim, Choon-Kyung
    • Journal of Families and Better Life
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    • v.24 no.5 s.83
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    • pp.113-128
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    • 2006
  • This study was to verify the effectiveness of the Life Review-Narrative group therapy program on decreasing depression and death anxiety in the elderly. The program was organized according to a course of life from childhood to old age. The objectives were for the elderly to enhance self-worth, to become aware of their solitary existence, to accept aging and death, to accept the life: both past and present, and to make the most of experiences in overcoming difficulties. For the most part, the program used reminiscence and re-authoring of the narrative therapy as counseling techniques. Thirty-two elderly people(16 in the experimental group, 16 in the control group) aged 60 years and over were randomly selected from patients at the Daegu Metropolitan City General Welfare Center. Two groups were identified as equivalents for the study in the pre-test. The program for the experimental group was implemented twice a week for 90 minutes per session over a 6-week period(Sep. 8-Oct.14. 2005). The pre-test(Sep. 8 2005), the post-test(Oct. 14. 2005) and the follow-up test(Nov. 14. 2005) were implemented in order to verify the effectiveness of the programs. The instruments used in the study were the Geriatric Depression Scale Short Form(Korean Version) and the Death Anxiety Scale. The data were analyzed using t-testing and One-Factor Repeated Measures ANOVA. This study supplemented other qualitative research methods in order to verify the variation in the depression and death anxiety in the elderly. The findings of the study were as follows: Significant decrease in the depression and death anxiety were reported in the experimental group. The control group however did not show any significant changes in the depression and death anxiety rates. The result of the post hoc multiple comparisons showed that the effects of the life review-narrative group therapy program has lasted effects on decreasing of the death anxiety. Nevertheless, the effects of the life review-narrative group therapy program on decreasing depression are not lasting. The study has limitations so further research is suggested.

A Contextual Study of the Pluralization of Sexuality Represented in Mainstream Fashion and Anti-Fashion Since the Late $19^{th}$ Century (19세기 후반 이후 주류패션과 반패션에 표현된 성의 다원화에 관한 맥락적 연구)

  • Choi, Kyung-Hee
    • Journal of the Korean Society of Costume
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    • v.57 no.5 s.114
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    • pp.166-182
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    • 2007
  • The purpose of this study is to reinterpret sexuality represented in fashion since the latter half of the 19th century in a contextual view, on the basis of Foucauldian idea of post-structural sexuality. As for research methodology, literary research was undertaken from the conception of sexuality to a historical review of the culture and dress. Foucault maintains the view of plural sexuality, which floats by power relationship between dominant and oppositional discourses in a specific historical context. In contextual approach sexual ideology codified in fashion since the latter 19C shows the following aspects: First, the traditional sexual ideology in the latter 19C is a capitalist value, which gives a priority to bourgeois man's profits, and the Victorian discourses of sexuality constructs the dichotomized fashion of the period. Next, the former half of the $20^{th}$ C is regarded as the period of conformity rather than opposition with various alternatives appropriated to the mainstream, so the traditional sexual ideology in fashion of this period is still preserved. Finally, in post-capitalism period of the latter 20C a variety of anti-fashion visualized plural sexuality from the enormous oppositional discourses. Although it doesn't all mean deconstruction of sexuality in fashion by the anti-fashion re-appropriated without oppositional meanings, pluralization of sexuality implies dynamics of sexual discourses in the next historical period. As a result, fashion since the latter 19C has been changed as a means for expressing age and sexual desire out of gender and class. And mainstream fashion in even postmodern period keeps the modern value on the center of the hegemonic heterosexual masculinity though the increase of Androgynous Femininity in women's fashion may connote the meaning of femininity. The plural sexuality represented in fashion has a contextual flexibility, thus sexuality floats with a specific socio-cultural context and fashion represents a masquerade as an identity vehicle.

Study on Ethnic's Major Characteristics Expressed in Modern Fashion -Focus on 2005 S/S - 2010 F/W Paris, Milan Collection- (현대 패션에 나타난 에스닉(Ethnic) 특성 분석에 관한 연구 -2005년 S/S부터 2010년 F/W까지 파리.밀라노 컬렉션을 중심으로-)

  • Kim, Young-Sam
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.11
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    • pp.1844-1858
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    • 2010
  • Ethnical tendency follows the current political, economical, and cultural influence eastwards, highlighting films, architecture and interiors as well as fashion. With this tendency, the ethnic outfits are expressed by various styles. This study analyzes the features of current ethnic styles with 1,535 ethnic image pieces from 2005 S/S to 2010 F/W of Pr${\^{e}}$t-${\'{a}}$-Porte in Paris and Milan. First, 'ethnic' is to refer to the distinct features of an ethnic group or a country. 'Ethnic look' refers to the adaptation or re-arrangement of various ethnic group's traditional costumes, dying, textile, patterns, color, silhouettes, and accessories. Second, the most popular ethnics in the modern fashion is the African style, followed by India, Japan, China, and Latin America in both collections. Third, the proportion of ethnics decreased, 2005 (14.9%), 2006 (12.8%) and 2007 (8.2%). In 2008 the proportion increased again. 2010 (27.3%) and compared 2010 to 2007, it increased by 20%. By season, S/S had 1.4 times more ethnic styles than F/W with the prevalence of African and Indian styles. Fourth, as of 2005, the ethnic style became colorful and went through changes to combine various images. This is from the polycentric tendency of co-existing various styles with a prevalence of low tone and various colors. It also shows warm colors in front to show a sense of nature.

The TV Audience's Traits, Media Usage and the Adoption of the Satellite DMB : Focus on the Understanding and Evaluation of the Local TV Audience (시청자 특성, 미디어 이용과 위성 DMB의 수용 : 지역 시청자의 인식과 평가를 중심으로)

  • Lee, Si-Hoon
    • Korean journal of communication and information
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    • v.28
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    • pp.141-169
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    • 2005
  • This study considered the factor of the adoption of the satellite DMB. This study focus on the TV audience's demographic traits and media usage. The results are follows : 1) the elder-aged group, high-educated group and car driver group have high intention to be subscriber for the satellite DMB service. 2) the white collar group and the middle income group have high intention to be subscriber for the satellite DMB service. 3) the many media use group and the many function use of mobile phone group have high intention to be subscriber for the satellite DMB service. 4) the local TV audience like the entertainment genre in video and audio service and the information genre in data service 5) the local TV audience don't mind of the re-transmission territorial broadcasting by the satellite DMB service.

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MATURE INSTRUMENT, IMMATURE TECHNOLOGY : IS NIR ANALYSIS OF HIGH MOISTURE MATERIALS A SERIOUS PROPOSITION\ulcorner

  • Berding, Nils
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.3124-3124
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    • 2001
  • The development and evolution of near infra-red spectroscopic (NIS) calibrations for high-moisture materials is an expensive proposition. Such investment is suspect unless the instrument, or instruments, on which calibrations were developed can be preserved intact or re-standardized as component replacements occurs. The objective of this paper is to detail the changes in performance of a six-year old instrument after maintenance in years five and six resulted in collection of spectral data that was increasingly removed from the calibration population. Calibrations for the analysis of mature sugarcane stalks, a high-moisture material, were developed successfully in 1995 using a broad sample population in terms of genetics, and spectral and temporal variation. The spectral library was further broadened in 1996. In 1997, 1999, 1999, and 2000, additional samples constituting 10% of the laboratories throughput were subjected to full component analyses using routine laboratory techniques. These samples were primarily random samples, but were complemented with samples that were significant for the spectral H statistic or for the component t statistic. In 1998, an additional calibration was developed for populations consisting of samples of either mature stalks (culms) or sucker culms. Substantial additional samples numbers were collected for this calibration in 1999 and 2000. Attempts to standardize the scanning spectrophotometer used for these calibrations with a second similar instrument in 1999 failed because the instruments were optically different, and standardization could not account for this. Maintenance adjustments were made to the remote reflectance probe of the original instrument in 1999, and replacement of its PbS detectors was done in 2000. Spectral data collected in 1999 and 2000 yielded spectral populations that were increasingly removed from the respective spectral populations on which the calibrations were developed. The mature stalk calibrations benefited marginally from evolutionary calib.

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Clinical Study of Acupuncture Theraphy of Gastrointestinal Side Effect of Levodopa: Focused on Idiopathic Pakinson's Disease Patients (레보도파제제의 위장관계 부작용에 대한 침치료 효과 연구-특발성 파킨슨병 환자를 대상으로-)

  • Yang, Dong-Ho;Lee, Kyung-Yun;Shin, Hyun-Seung;Jo, Song-Hyun;Lim, Chang-Sun;Lim, Jun-Hyuk;Yun, Suk-Hoon;Lee, Han;Kang, Myoung-Jin
    • Journal of Acupuncture Research
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    • v.27 no.6
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    • pp.11-21
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    • 2010
  • Objective : This study was aimed at investigating the therapeutic effects of acupuncture on gastrointestinal side effect of Levodopa on idiopathic Pakinson's disease patients. Methods : The subjects of this study were 42 patients with idiopathic Parkinson's disease. We divided them into two groups; acupuncture treatment group, no treatment group. We treated the former group with acupuncture therapy focusing on gastrointestinal side effect of Levodopa while administering Levodopa as well. And the latter group was also dosed up with Levodopa without acupuncture therapy. To see the effect of acupuncture treatment clearly, we used gastrointestinal syndrome rating scale (GSRS) and visual analog scale (VAS) and compared the GSRS grade and VAS score of two groups statistically, after 1, 2, 3, 4 weeks since they have been under the treatment. Results : This study suggests that the group who has been treated with acupuncture on gastrointestinal side effect of Levodopa on idiopathic pakinson's disease patients showed higher GSRS grade and VAS score than the one that has not. But, We could't find statistical significance between the two groups on improvement of GSRS grade and VAS score. Conclusions : These results proved that acupucture theraphy might be available for re lieving symptoms related with gastrointestinal side effect of Levodopa than the one that has not. But further studies are necessary.