• Title/Summary/Keyword: Existence Value

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Damage detection in beam-like structures using deflections obtained by modal flexibility matrices

  • Koo, Ki-Young;Lee, Jong-Jae;Yun, Chung-Bang;Kim, Jeong-Tae
    • Smart Structures and Systems
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    • v.4 no.5
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    • pp.605-628
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    • 2008
  • In bridge structures, damage may induce an additional deflection which may naturally contain essential information about the damage. However, inverse mapping from the damage-induced deflection to the actual damage location and severity is generally complex, particularly for statically indeterminate systems. In this paper, a new load concept, called the positive-bending-inspection-load (PBIL) is proposed to construct a simple inverse mapping from the damage-induced deflection to the actual damage location. A PBIL for an inspection region is defined as a load or a system of loads which guarantees the bending moment to be positive in the inspection region. From the theoretical investigations, it was proven that the damage-induced chord-wise deflection (DI-CD) has the maximum value with the abrupt change in its slope at the damage location under a PBIL. Hence, a novel damage localization method is proposed based on the DI-CD under a PBIL. The procedure may be summarized as: (1) identification of the modal flexibility matrices from acceleration measurements, (2) design for a PBIL for an inspection region of interest in a structure, (3) calculation of the chord-wise deflections for the PBIL using the modal flexibility matrices, and (4) damage localization by finding the location with the maximum DI-CD with the abrupt change in its slope within the inspection region. Procedures from (2)-(4) can be repeated for several inspection regions to cover the whole structure complementarily. Numerical verification studies were carried out on a simply supported beam and a three-span continuous beam model. Experimental verification study was also carried out on a two-span continuous beam structure with a steel box-girder. It was found that the proposed method can identify the damage existence and damage location for small damage cases with narrow cuts at the bottom flange.

Dimethylsulfide (DMS) in the Coastal Areas of the Cheju Island, Korea (제주도 연안해역을 중심으로 한 DMS 농도의 관측)

  • 김기현;이강웅;허철구;강창희
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.2
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    • pp.161-170
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    • 1997
  • The concentrations of dimethylsulfide (DMS) were determined using samples collected from a station located at Kosan, Cheju Island during two field campaigns held in December 1996 and January 1997. The atmospheric DMS concentrations measured at 6-hr intervals during the entire campaign periods, after excluding a few extreme values, spanned in the range of 14 to 410 pptv with mean and 1 SD value of 127 $\pm$ 94 pptv (N=42). Between two month periods during which the field campaigns were conducted, a notable reduction in DMS levels was observed which was comparable to the dramatic shift in air temperature. A considerable difference was also noted in DMS levels, when data were grouped by day/night basis. The cause of unexpected, high day-to-night DMS ratios is best explained in terms of high efficiency of daytime source processes relative to low efficiency of nighttime sink processes due to the characteristics of the study location. The surface water DMS of the study site, although scarcely measured, also behaved similarly to its atmospheric counterpart with its range from 0.3 to 19 nM (N=11). When correlation analysis was conducted between the atmospheric DMS concentration and other concurrently determined parameters, significant correlations were observed from most basic meteorological parameters such as windspeed, relative humidy, and air temperature. However, the existence of "not-so-strong" correlations between air temperature and DMS concentrations relative to other ones indicated that the effect of temperature on DMS behavior must be reflected in more complicated manners at the study site. The sea-to-air flux of DMS was approximated through an application of the mass-balance flux calculation method of Wylie and de Mora (1996) under the assumption that sink mechanism within the marine boundary layer is in steady-state condition with its counterpart, source mechanism. Based on this estimation method, we reached a conclusion that oceanic DMS emitted from the southwest sea of the Korean Peninsula can amount to approximately 9 $\sim$ 36 Gg S $yr^{-1}$.$yr^{-1}$.

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Study of Properties of High-K Strontium Oxide Alignment Layer Using Solution Process for Low Power Mobile Information Device (저전력 휴대용 통신단말을 위한 Solution Process를 이용한 고 유전율 Strontium Oxide 배향막의 특성 연구)

  • Han, Jeong-Min;Kim, Won-Bae
    • Journal of Satellite, Information and Communications
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    • v.10 no.2
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    • pp.90-94
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    • 2015
  • We stuidied liauid crystal alignment treatment using solution process for making thin oxide layer in liquid crystal display. It is the one of very effient and popular process in making thin oxide layer in electronical industrial fields. Particularly, this process has highly potential value in liquid crystal display industrial fields because it cause automatically induced alignment process without tranditional alignment process in liquid crystal alignment process. We made several different kinds of mol density solutions using strontium oxide solution. And those solutions were treated for solidification layers using annealing process for 2 hours. And we stuided pretilt angle properties of these alignment layers of strontium oxide for clarifying the relationship of liquid crystal molecules and thin strontium oxide layer. And we also tested the existence of strontium oxide thin layer on substrate using XPS measurement. We expected the hig gain of electro-optical properties in liquid crystal display using strontium oxide thin layer because it has high K property material than the other metal-based oxide layers. In this results, we measured 1.447 to 1.613 thresholds volts as 0.1 mol to 0.4 mol density in 0.1 mol density steps. This is significant better characteristics than conventional liquid crystal display as higher than 1.85 thresholds volts. And it make possible to making next-generation liquid crystal display which present low-power consumption and wide gray scale in liquid crystal display.

Moringa oleifera Lam: Targeting Chemoprevention

  • Karim, Nurul Ashikin Abd;Ibrahim, Muhammad Din;Kntayya, Saie Brindha;Rukayadi, Yaya;Hamid, Hazrulizawati Abd;Razis, Ahmad Faizal Abdull
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.3675-3686
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    • 2016
  • Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as ''murungai'' or ''kelor''. Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research need to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development.

Orthodox Oriental Medicine in East Asia used for Canine Diseases (개의 질병에 사용된 동아시아 전통의학 처방 연구)

  • Park, Sang-Young;Oh, Jun-Ho
    • Journal of Haehwa Medicine
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    • v.22 no.1
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    • pp.57-70
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    • 2013
  • Objective: Today, the public concern for 'Companion Animal" as a family member is ever increasing. Accordingly, the cases of traditional veterinary medicine treatment targeting a companion animal has been increasing, but the traditional records in literature about this have hardly ever been introduced to academic circles. Hereupon, this writing is intending to collect the prescriptions, which were once used for treating canine diseases, in order to report them to academic circles first. Method: This writing recorded the information about canine diseases and their treatment from the books related to the orthodox oriental medicine in East Asia, and analyzed their meanings. Result: Intial records about canine diseases are found in East Asian traditional medicine books including "Bonchoseubyu"(741), "Ilwhajajegaboncho"(unidentifiable period), "Jeungryuboncho"(1082), etc. The disease perceived by humans at that time was "gwa"(a boil) which is a kind of skin ailments. In addition, these medicine books show that people at that time concentrated on the value of use of a dog as meat rather than a pain of a dog's diseases. "Hwalsujaju"(1873)which was established during the Qing Dynasty leaves the most abundant data on canine diseases. This book perceived a dog as a precious existence watching over human housing and property, according to which, canine diseases and treatment methods are subdivided. The prescriptions for a dog's disease in our country are identifiable only in "Jeungbodanbangshinpyeon"(1913)과 "Bijeongmanbyeongtongchibeop"(1933). These books include the prescriptions not only for a dog's disease but also for a disease of a cow, horse, sheep, chicken, and pig, etc. which are familiar to us. Conclusion: The prescriptions used for a dog in East Asia were different from those for people. It was found that they used a medicine noticeably for external application for easy treatment, and in case of the use of an internal medicine, they adopted a method of getting dogs to take a medicine mixed with rice or porridge for dogs. Such a clue will be applied to the traditional- medicine-based treatment of a companion animal for the time to come.

Acceptance Test and Clinical Commissioning of CT Simulator

  • An, Hyun Joon;Son, Jaeman;Jin, Hyeongmin;Sung, Jiwon;Chun, Minsoo
    • Progress in Medical Physics
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    • v.30 no.4
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    • pp.160-166
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    • 2019
  • This study examined the clinical use of two newly installed computed tomography (CT) simulators in the Department of Radiation Oncology. The accreditation procedure was performed by the Korean Institute for Accreditation of Medical Imaging. An Xi R/F dosimeter was used to measure the CT dose index for each plug of the CT dose index phantom. Image qualities such as the Hounsfield unit (HU) value of water, noise level, homogeneity, existence of artifacts, spatial resolution, contrast, and slice thickness were evaluated by scanning a CT performance phantom. All test items were evaluated as to whether they were within the required tolerance level. CT calibration curves-the relationship between CT number and relative electron density-were obtained for dose calculations in the treatment planning system. The positional accuracy of the lasers was also evaluated. The volume CT dose indices for the head phantom were 22.26 mGy and 23.70 mGy, and those for body phantom were 12.30 mGy and 12.99 mGy for the first and second CT simulators, respectively. HU accuracy, noise, and homogeneity for the first CT simulator were -0.2 HU, 4.9 HU, and 0.69 HU, respectively, while those for second CT simulator were 1.9 HU, 4.9 HU, and 0.70 HU, respectively. Five air-filled holes with a diameter of 1.00 mm were used for assessment of spatial resolution and a low contrast object with a diameter of 6.4 mm was clearly discernible by both CT scanners. Both CT simulators exhibited comparable performance and are acceptable for clinical use.

Strength and Moment-Curvature Relationship of HCFT Columns under Eccentric Load (편심압축이 작용하는 HCFT기둥에 대한 내력특성과 모멘트-곡률의 곤계)

  • 이승조;박정민;김화중
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.864-873
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    • 2002
  • Recently, CFT Column has reported a lot of study result, because a CFT column has certain superior structural properties as well as good productivity, execution efficiency, and improved rigidity over existing column. However, CFT column still has problems clearing the capacity evaluation between its steel tube member and high-strength concrete materials. Also, high-strength concrete filled steel square tube column(HCFT) examined numerical value explanatorily about transformation performance(M-ø) of when short-column receives equal flexure-moment from axial stress on research for concrete. hnd, with basis assumption, executed development of analysis program of moment-curvature relation for analytic analysis of transformation performance of HCFT section that get by an experiment. This study investigated to properties of structural(capacity, curvature), through a series of experiments for HCFT with key parameters, such as strength of concrete(600kgf/$\textrm{cm}^2$), D/t ratio, slenderness ratio(λ) and concrete kinds under eccentric load. And, I executed comparative analysis with AISC-LRFD, AIJ and Takanori Sato etc. and experiment result that is capacity design formula.

Critical Barriers to the Practice of Effective Cost Planning in the Ghanaian Construction Industry

  • Kissi, Ernest;Adjei-Kumi, Theophilus;Badu, Edward
    • Journal of Construction Engineering and Project Management
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    • v.6 no.2
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    • pp.8-15
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    • 2016
  • Cost planning practices in the construction industry worldwide has gained much popularity in recent times due to economic recession and stringent measures that various procurement laws prescribe in most developed and developing countries. Nevertheless, these practices in developing countries such as Ghana are constrained with the existence of critical barriers that render them non-effective and hence, accounting for the numerous abandonment of both private and public projects. Consequently, this study was enunciated with the aim to examine the critical barriers to the practice of effective cost planning in the Ghanaian construction industry. Through an in-depth literature review and a pilot survey, questionnaires were designed and administered to quantity surveyors. Data generated from the field survey was subjected to principal component analysis. The findings of the study revealed weak cost planning knowledge base, poor cost databases and understanding, inadequate designs and planning and external conditions are the major barriers to cost planning practices in the Ghanaian construction industry. The need for this study cannot be doubted since it provides an insight for experts in the construction industry on the barriers of the practice of cost planning in the industry. The awareness of these barriers will therefore facilitate efficient and effective efforts to resolve them. A future study is thereby proposed by this study to explore effective cost planning practices in the Ghanaian construction industry that will ensure private and public stakeholders get value for their money invested.

A comparative study of electrical properties of arachidic acid LB films in the Al/LB/Al and Au/LB/Au electrode structure (Al/LB/Al, Au/LB/Au 전극 구조에서 arachidic acid LB막의 전기적 특성에 관한 비교 연구)

  • 오세중;김정수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.10
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    • pp.1311-1316
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    • 1995
  • The electrical properties of the Langmuir-Blodgett (LB) films layered with arachidic acid were studied at the room temperature. The sample was formed with 2 different structure ; One was Al/LB/Al and the other was Au/LB/Au. The precise structure of Al/LB/Al was considered as Al/Al$_{2}$O$_{3}$/LB/Al, because the natural oxide layer was formed on surface of lower Al electrode. The electrical conductivity of Al/Al$_{2}$O$_{3}$/LB/Al structure was determined the value of 3.5 * 10$^{-14}$ S/cm from the measurement of current-voltage (I-V) characteristics. The sample with the structure of Au/LB/Au was made to eliminate the influence of oxide layer in the electrical properties of the LB films. The short circuit current was observed in this sample from the I-V characteristics. To verify the reason of short circuit current generation, copper decoration method was employed to the 15 layers of LB films deposited on the Al and Au electrode each. The defects were shown on the films deposited with Au electrode. This results means that the defects on the LB films which layered with the Au electrode were contributed to the short circuit current. Several films (15, 31, 51, 71L) were deposited on the Au electrode and measured the size of defects with the copper decoration method. The size of defects becomes smaller as the film layer was increased. We conclude that the existence of defects affects the short circuit current generation.

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Properties of Working Electrodes with Nano YBO3:Eu3+ Phosphor in a Dye Sensitized Solar Cell

  • Noh, Yunyoung;Choi, Minkyoung;Kim, Kwangbae;Song, Ohsung
    • Journal of the Korean Ceramic Society
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    • v.53 no.2
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    • pp.253-257
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    • 2016
  • We added 0 ~ 5 wt% $YBO_3:Eu^{3+}$ nano powders in a scattering layer of a working electrode to improve the energy conversion efficiency (ECE) of a dye sensitized solar cell (DSSC). FESEM and XRD were used to characterize the microstructure and phase. PL and micro Raman were used to determine the fluorescence and the composition of $YBO_3:Eu^{3+}$ phosphor. A solar simulator and a potentiostat were used to confirm the photovoltaic properties of the DSSC with $YBO_3:Eu^{3+}$. From the results of the microstructure and phase of the fabricated $YBO_3:Eu^{3+}$ nano powders, we identified $YBO_3:Eu^{3+}$ having particle size less than 100 nm. Based on the microstructure and micro Raman results, we confirmed the existence of $YBO_3:Eu^{3+}$ in the scattering layer and found that it was dispersed uniformly. Through photovoltaic properties results, the maximum ECE was shown to be 5.20%, which can be compared to the value of 5.00% without $YBO_3:Eu^{3+}$. As these results are derived from conversion of light in the UV range into visible light by employing $YBO_3:Eu^{3+}$ in the scattering layer, these indicate that the ECE of a DSSC can be enhanced by employing an appropriate amount of $YBO_3:Eu^{3+}$.