• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1000-1013
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• 2014

This paper presents some of the efforts by the authors towards numerical prediction of springing of ships. A time-domain Higher Order Boundary Element Method (HOBEM) based on cubic shape function is first presented to solve a complete second-order problem in terms of wave steepness and ship motions in a consistent manner. In order to avoid high order derivatives on the body surfaces, e.g. mj-terms, a new formulation of the Boundary Value Problem in a body-fixed coordinate system has been proposed instead of traditional formulation in inertial coordinate system. The local steady flow effects on the unsteady waves are taken into account. Double-body flow is used as the basis flow which is an appropriate approximation for ships with moderate forward speed. This numerical model was used to estimate the complete second order wave excitation of springing of a displacement ship at constant forward speeds.

• Journal of Communications and Networks
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• 제6권2호
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• pp.163-172
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• 2004

Ultra Wide Bandwidth (UWB) spread-spectrum techniques will playa key role in short range wireless connectivity supporting high bit rates availability and low power consumption. UWB can be used in the design of wireless local and personal area networks providing advanced integrated multimedia services to nomadic users within hot-spot areas. Thus the assessment of the possible interference caused by UWB devices on already existing narrowband and wideband systems is fundamental to ensure nonconflicting coexistence and, therefore, to guarantee acceptance of UWB technology worldwide. In this paper, we study the coexistence issues between an indoor UWB-based system (hot-spot) and outdoor point to point (PP) links and Fixed Wireless Access (FWA) systems operating in the 3.5 - 5.0 GHz frequency range. We consider a realistic UWB master/slave system architecture and we show through computer simulation, that in all practical cases UWB system can coexist with PP and FWA without causing any dangerous interference.

• 한국정보통신학회논문지
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• 제5권4호
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• pp.716-722
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• 2001

본 논문은 3세대 및 그 이상의 무선망에 대한 기본적인 망의 구조를 IP를 바탕으로한 무선망으로 정의하고 이때 무선 접속망에서의 폭주제어 방법을 제안한다. 기본적으로 제안하는 방법은 ECN(Explicit Congestion Notification)을 바탕으로 하나 무선망과 IP망의 Broadcasting에서의 장점을 이용하여 ECN Broadcasting을 무선 서브망에서 수행하도록 하여 미래의 무선망에서의 이동성 지원으로 인한 폭주제어에 있어서 효율성을 갖도록 하였다.

• 한국안전학회지
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• 제37권6호
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• pp.60-70
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• 2022

This paper proposes an optimal design method of a seismic reinforcement system for the seismic performance of adjacent asymmetric-stiffness structures with viscous dampers. The first method considers plan asymmetry for efficient seismic reinforcement, and evaluates the seismic performance of optimal design applied to two cases of modeling: adjacent stiffness-asymmetric structures and adjacent stiffness-symmetric structures. The second method considers the response of asymmetric structures to derive the optimal objective function, and evaluates seismic efficiency of the objective function applied to two cases of responses: horizontal displacement and torsion. Numerical analyses are conducted on 7- and 10-story structures with a uni-asymmetric-stiffness plan using six cases of historic earthquakes, normalized to 0.4g. The results indicate that the seismic performance is excellent as modeled by adjacent asymmetric-stiffness structures and how much horizontal displacement is applied as the objective function.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권4호
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• pp.506-517
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• 2015

This paper presents a 1.248 Gb/s - 2.918 Gb/s low-power receiver MIPI-DigRF M-PHY with a fully digital frequency detection loop. MIPI-DigRF M-PHY should be operated in a very short training time which is $0.01{\mu}s$ the for HS-G2B mode. Because of this short SYNC pattern, clock and data recovery (CDR) should have extremely fast locking time. Thus, the quarter rate CDR with a fully digital frequency detection loop is proposed to implement a fast phase tracking loop. Also, a low power CDR architecture, deserializer and voltage controlled oscillator (VCO) are proposed to meet the low power requirement of MIPI-DigRF M-PHY. This chip is fabricated using a $0.11{\mu}m$ CMOS process, and the die area is $600{\mu}m{\times}250{\mu}m$. The power consumption of the receiver is 16 mW from the supply voltage of 1.1 V. The measured lock time of the CDR is less than 20 ns. The measured rms and peak jitter are $35.24ps_{p-p}$ and $4.25ps_{rms}$ respectively for HS-G2 mode.

• 한국건설순환자원학회논문집
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• 제4권4호
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• pp.363-370
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• 2016

경량 지오폴리머는 경량 시멘트 콘크리트보다 단순한 공정으로 제조가 가능하고 탁월한 내열 성능까지 갖춘 재료이다. 고형 지오폴리머의 밀도는 발포제와 지오폴리머 배합물과의 화학반응으로 발생되는 가스가 기공을 형성함으로서 감소시킬 수 있기 때문이다. 본 논문에서는 다양한 함량의 알루미늄 분말을 첨가하여 다공성 지오폴리머의 특성에 어떤 영향을 주는지 살펴보고자 하였다. 경량 지오폴리머의 겉보기 밀도는 알루미늄 분말 함량이 0.025, 0.05, 0.10wt% 범위에서 0.7에서 $1.2g/m^3$로 나타났는데 이는 고형 지오폴리머의 겉보기 밀도 값 $1.96g/cm^3$의 약 37~60%에 해당하였다. 경량 다공성 지오폴리머의 압축강도는 고형 지오폴리머의 압축강도 45MPa의 6~18%에 불과하였다. 고형 지오폴리머와 경량 지오폴리머 겔의 미세조직 형상은 유사하였다. 폴리프로필렌 섬유를 첨가한 지오폴리머 배합물의 작업성은 섬유 보강 시멘트 콘크리트에서와 마찬가지로 개선될 필요가 있다. 경량 다공성 지오폴리머는 현무암과 유사한 외관뿐만 아니라 뛰어난 내열 성능을 갖기 때문에 타일이나 보드 등 건축용 내장재로서의 활용 가능성이 높다고 본다.

• 한국건축시공학회지
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• 제23권6호
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• pp.663-671
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• 2023

본 연구에서는 목질계 바이오매스(Bio-SRF, 우드펠릿)를 연료로 사용하는 발전소 3곳에서 배출된 4종의 목질계 플라이애시(FA)의 재활용성을 실험적으로 검토하였다. FA의 물리 분석(입형, 입도분포, 분말도, 밀도)과 화학 분석(화학조성, 중금속 함량)을 수행하였고, KS L 5405에 준하여 혼입률 5~20%의 모르타르 시험체를 제작하고 플로우와 압축강도를 측정하였다. 4종의 FA는 입경 약 20~30㎛, 밀도 약 2.3~2.5g/cm³, 분말도 2,600~4,900cm²/g, SiO₂, Al₂O₃, Fe₂O₃, CaO 성분이 약 50~90%를 차지하고 있으며, 염소와 SiO₂ 함량을 배제하고 KS L 5405의 FA 2, 3형과 유사한 특성을 보였다. 모르타르 혼입 평가 결과, 펠릿 연소 FA는 5~20% 혼입 범위에서 모르타르 압축강도는 34~47MPa로 측정되었다. 목질계 연료 100%를 연소한 FA는 혼화재 대체재로서 재활용성이 높다고 평가된다.

• 한국환경복원기술학회지
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• 제22권6호
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• pp.41-61
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• 2019

The purpose of this study was carried out to present the basic data for constructing a ecological stream, Shindangcheon stream located in Gyeongju-si, Gyeongsangbuk-do, South Korea. From August 2017 to June 2019, a total of 7 surveys were conducted. The numbers of vascular plants were summarized as 388 taxa including 75 families, 246 genera, 360 species, 4 subspecies, 19 varieties, 2 forms and 3 hybrids. The most families of taxa were Poaceae (59 taxa), Asteraceae (47 taxa), Fabaceae (27 taxa), Rosaceae and Cyperaceae (20 taxa, respectively), and Polygonaceae and Brassicaceae (15 taxa, respectively). The rare plant was Aristolochia contorta Bunge, and the Korean endemic plants were 4 taxa, such as Populus × tomentiglandulosa T.B.Lee, Salix koriyanagi Kimura ex Goerz, Lespedeza maritima Nakai, and Weigela subsessilis (Nakai) L.H.Bailey. The specific plants by floristic region found in this site were 13 taxa comprising 8 taxa of grade I, 4 taxa of grade III, and 1 taxon of grade IV. The naturalized plants were 73 taxa, such as Fallopia dumetorum (L.) Holub, Persicaria orientalis (L.) Spach., Potentilla supina L. var. ternata Pterm., and so forth. The invasive alien plants were 6 taxa, such as Rumex acetosella L., Sicyos angulatus L., Solanum carolinense L., Ambrosia artemisiifolia L., Lactuca serriola L., and Symphyotrichum pilosum (Willd.) G.L.Nesom..

• KIEAE Journal
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• 제13권3호
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• pp.79-89
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• 2013

The purpose of this study is to evaluate the airtightness performance of New Han-ok and to supply fundamental data for standards establishment. Air leakage testings were accomplished by means of blower door test in 26 bedrooms of 16 Han-oks located in Jeonnam happy villages. Followings are results. 1) Air change per hour at 50 Pa(ACH50) is located on 8.42~78.38. 2) No correlation between ACH50 and volumes, floor area, above grade surface area. 3) The more wood structural elements are exposed, attached spaces, wooden sliding and casement windows, the less airtightness performance. 4) An Airtightness with ACH50/20(NL, Normalized leakage) is located on 0.42~3.92 and building leakage class following F(4%), G(11%, sufficiently leaky, No need mechanical ventilation), H(4%, Need of cost-effective tightening), I(31%), J(50%) by a single-story house the normalized leakage of ASHRAE.

• 복식
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• 제32권
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• pp.293-312
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• 1997

Deconstructionism is a philosophical stream in the latter half of 20'th century which goes against western metaphysics and tries to deconstruct the dualism e.g. eastern/west-ern man/woman. Its main concepts are 'indi-vidual' 'other' 'difference' 'restoration of the repressed' 'decentralization' 'Today it shows strong influences in literature art, and other social fields. This study investigated inner meanings and exterior forms represented in clothing on the base of Jacques Derrida's theory in order to re-search modes of deconstruction in is. And it compared clothing with architecture among other genres of art in order to discover similarities between through and modes of art in a certain period. For illuminating concept of deconstruction I referred to the literatures of preceding studies and for deconstruction's characteristics in both clothing and architec-ture I referred work's collection book $\ulcorner$collec-tions$\lrcorner$ and other related books dealing from 1960's to this point. As a rsult there are four modes of decons-truction in both clothing and architecture as follows; 1) Differenance which is a concept of the dif-ference in time and space as being trace. 2) In termeaning of meanings which is not present in reality but re-interpreted a new in the future. 3) Interxtuality in which a texte is not alone but with others 4) Dis.De phenomenon in which distortion and fragmentation forms occur as the result of the denial of perfection and reson. There are characteristics of modes of de-construction in clothing as follows; 1) Differance; R.Gigli, P. Rabanne. G.Bersace, V.Westwood are representatives of the cloth-ing which is combined with the past the pres-ent and the future or is re-viewed as the clothing of the past in the present point of view. J. Watanabe R. Dawakubo I miyake are representatives of the clothing which is out-date but re-viewed in the sense of recollec-tion and re-usage. 2) Intermeaning of meanings: R. kawakubo I, Miyake Y,Yamamoto are representatives of the clothing which is incomplete but re-interpreted in the future and appears to be new-fashioned according to ways of bnding wearing throwing on and tying J.C. Castel-bajac K.Hamnett S.Sprouse are representa-tives of the clothing which is made up of ab -stract forms scribbling or symbolic letters which appears to be different according to view-point of observers. 3) Intertextuality ;J.P.Gaultier K.Hamnett, Comme des Gar ons are representatives of intertextuality of gender which avoids the 여-ality of man/woman J.P Gaultier G,Versace J. galliano are representatives of the intertex-tuality of time place and occasion which mixes temporality extensity and purposiveness. J.P Gaultier G,Versace are representatives of the intertextuality of coordination which combines items different in image purpose and use. P.Rabanne A,Courr ges R,Gernreic I,Miyake are representatives of the intertextuality of mat-ter which uses heterogeneous matter different from cloth. 4) Dis.De-phenomenon: R, Kawakubo I.Mi-yake J.P.Gaultier are representatives of the de-composition which discloses distortion and exag-geration of form through destructing the estab-lished way of construction J.Galliano R.Kawa-kubo Devota Y Lomba arte representatives of the decentring which restores the repressed and the alienated on the one hane and shows front-centrality on the other. Comme des Gar ones is representative of the discontinuity because of which right and left up and down are not in har-mony with one another. J,Galliano J.P,Gaultier T,Mugler are representatives of the disruption by way of which one makes one's body exposed through intentional slashes or holes. As a consequence deconstructionism enabled us to investigate similarities between through of deconstruction and modes of art interms of diffrance Intermeaning of meanings intertextuality and Dis De-phenomenon. And we found that deconstruction was a phase of development in that it as a all-comprising and multiple concept tries to pursue the new through deconstruction.