• Journal of Power Electronics
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• v.17 no.2
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• pp.432-441
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• 2017

Grid voltage feedforward is extensively used for controlling grid-connected converters. However, the conventional voltage feedforward control reduces the stability margins of the converter connected to a high-impedance grid. The effect mechanism of voltage feedforward on the grid-connected converter control under high-inductive conditions of the grid impedance is clearly explained in this study using the equivalent transformations of control block diagrams. Results show that the delay produced by the digital control is the root cause of this effect. An improved voltage feedforward strategy, in which a bandpass filter (BPF) is introduced into the feedforward path, is proposed to strengthen the converter's robust stability against grid impedance variations. The selection method of the BPF's bandwidth is also provided considering the tradeoff between the response speed to the grid voltage sag and the system's robust stability. The converter can work stably over a wide range of the grid impedance through the proposed approach. Simulation and experimental results fully verify the effectiveness of the BPF-based voltage feedforward strategy.

• Steel and Composite Structures
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• v.26 no.2
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• pp.197-211
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• 2018

The study presents the earthquake performance of the Bosphorus Bridge under multi-point earthquake excitation considering the spatially varying site-specific earthquake motions. The elaborate FE model of the bridge is firstly established depending on the new considerations of the used FEM software specifications, such as cable-sag effect, rigid link and gap elements. The modal analysis showed that singular modes of the deck and the tower were relatively effective in the dynamic behavior of the bridge due to higher total mass participation mass ratio of 80%. The parameters and requirements to be considered in simulation process are determined to generate the spatially varying site-specific ground motions. Total number of twelve simulated ground motions are defined for the multi-support earthquake analysis (Mp-sup). In order to easily implement multi-point earthquake excitation to the bridge, the practice-oriented procedure is summarized. The results demonstrated that the Mp-sup led to high increase in sectional forces of the critical components of the bridge, especially tower base section and tensile force of the main and back stay cables. A close relationship between the dynamic response and the behavior of the bridge under the Mp-sup was also obtained. Consequently, the outcomes from this study underscored the importance of the utilization of the multi-point earthquake analysis and the necessity of considering specifically generated earthquake motions for suspension bridges.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.2
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• pp.185-206
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• 2000

Das Wortspiel $hei{\ss}t$ die spielerische $Ver\"{a}nderung$ eines Wortes zum Zwecke $\"{u}berraschender$ Wirkungen, und die Werbetexter betrachten es monentan als ein beliebtes, wirkungsvolles Ausdrucksmittel $f\"{u}r$ die Werbeanzeigen. (1) Sag mal, wie war eigentlich dein erstes Mal? Und wie oft machst du es in der Woche? Und was sagt deine beste Freundin dazu? -Gesichtsreinigungsmittel Clearasil Complete(Janich, 1999:146) (2) 대장님 힘 내세요! 뒷일은 제가 책임지겠습니다. -아락실 (3) 당신은 철없는 여자. -헤모큐 Das Wortspiel $l\"{a}{\ss}t$ den Referenzbezug ausweiten, vage oder $ungew\"{o}hnlich$ werden. Dadurch werden konventionelle Referenzerwartungen der Rezipienten verletzt und unterbrochen. Wortspiele mit Homonyme, Polyseme, Wortkreuzungen, und Referenzspiele sind sehr $h\"{a}ufig$, und die syntaktische und typographische Spiele dagegen eher selten. Die Wirkung des Wortspiel beruht auf die $Ambiguit\"{a}t$ eines Wortes. Aber zwischen der$Ambiguit\"{a}t$ und der Vagheit gibt es den $un\"{u}bersehbaren$ referenziellen Unterschied. $W\'{a}hrend$ diese, die durch die pragmatische Mehrdeutigkeit oder die Unbestimmtheit charakterisiert ist, mit der in einer $\"{A}u{\ss}erung ausgedr\"{u}ckten$ Vorstellung zu tun hat, handelt es bei jener um die Probleme der linguistischen Kategorien an, die unter lexikalischem, semantischem, und syntaktischem Aspekt mehrfach zu spezifizieren sind. Daher $k\"{o}nnen$ den wortspielerischen $Ausdr\"{u}cken$ mehere Interpretationsmoglichkeiten zugeordnet werden. Durch Wortspiele wird die Eindeutigkeit eines Wortes absichtlich aufgehoben, so $da{\ss}$ mehere denotativen Bedeutungen aktiviert werden. Dabei liegt eine semantische Konzentration oder ein semantisches Spannungsverhaltnis vor, Diesbezuglich $erf\"{u}llt$ das Wortspiel zugleich die Funktion, Aufmerksamkeit des Rezipienten auf den geworbenen Inhalt zu wecken, und $f\"{o}rdert$ das Interesse am Werbetext.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.1
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• pp.13-17
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• 2010

Ten numbers of plants, based on their medicinal value, were used to test their efficacy against virosis (caused by cytoplassmic polyhedrosis virus) in tasar silkworm, Antheraea mylitta Drury. in indoor rearing conditions. The aqueous extracts of leaf of Azadirichita indica (neem), Acharanthus aspera, Psoralea corylifolia, Asparagus racemosus, Adhatoda zelanica (Basak), Andrographis paniculata (Kalmegh), Moringa oilephera (sahjan), whole plant of Phyllanthus urinaria (Bhuiamla), Centella asiatica (Veng sag) and Curcuma longa (Haldi powder) in different concentrations were used for containment of virosis in silkworm larvae. The tasar silkworm larvae were orally inoculated with PIBs ($1\times10^6$) of AmCPV in $2^{nd}$ instar and treated with plant extracts in each instar ($2^{rd}$ instar onwards). The mortality due to virosis was recorded during larval period. The plant extracts, irrespective of their concentrations, were found effective in suppressing the virosis where P. urinaria reduced the virosis to 56.90% followed by A. paniculata (53.82%) and least in C. asiatica (5.15%). The lowest pooled larva mortality 36.99% was recorded in the treatment of P. urinaria. Comparatively higher larva mortality 39.91% was observed with the treatment of A. paniculata. The highest larva mortality in treatment was with C. asiatica (81.99%). In treated control larva mortality was 86.50%.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.21 no.4
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• pp.271-277
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• 2018

Purpose: Familial Mediterranean fever (FMF) is an auto inflammatory disease characterized by periodic fever, synovitis and serositis. Patients may be admitted to gastroenterology units due to gastrointestinal symptoms. In this study; we aimed to analyze endoscopic findings and diagnostic utility of endoscopic procedure in children with FMF. Methods: Patient with FMF that was performed endoscopy for the gastrointestinal symptoms were included to the study (39 of 164 patients, 53 procedure). A control group was randomly designed as age and gender matched four endoscopic procedures per one endoscopic procedure of patients with FMF (n=212). Results: No different was found between the patients and control group in esophagogastroscopy findings. However, the diagnosis of gastrointestinal pathology was made by esophagogastroscopy in 46.2% patients. Colonoscopic examination revealed that the frequency of inflammatory bowel disease (IBD) was higher in undiagnosed patients compared to both the control group (50.0% vs. 6.9%, p<0.05, odds ratio [OR]:13.4 and 95% confidence inteval [95% CI]: 2.1-84.3) and the patients under colchicine treatment (50.0% vs. 8.3%, p<0.05, OR: 11 and 95% CI: 0.8-147.8). Colonoscopic procedure that was made after the diagnosis was found to provide contribution by 16.7% in determining the etiology of the additional symptoms. Conclusion: Patients with FMF may be admitted to pediatric gastroenterology outpatient clinic prior to diagnosis or during the follow-up period. The frequency of IBD is high in undiagnosed patients with FMF. Endoscopic procedures may be helpful in these patients for the diagnosis accompanying mucosal lesions.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.38-43
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• 1990

Effects of concentration (5-8%, db) and heating temperature $(80^{\circ}C-95^{\circ}C)$ on rheological of mungbean starch were examined. The pasting curve by amylograph revealed no peak viscosity and the viscosity continued to increase during cooking, regardless the starch concentrations. Mungbean starch paste showed a pseudoplastic flow behavior with yield stress. The consistency index of paste increased as the heating temperature was raised at a given concentration. However, flow behavior index showed opposite trend. The percent sag of starch gel stored at $4^{\circ}C$ decreased with the increase of concentration and heating temperature. The firmness of fresh gel prepared from 7 and 8% starch suspensions by heating at $95^{\circ}C$ for 15 min with amylograph was about 2-times higher than that of 6% gel. However, the time constant, reciprocal of rate constant, of starch gels during aging at $4^{\circ}C$ was not significantly influenced by concentrations and heating temperatures.

• Korean Journal of Optics and Photonics
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• v.25 no.5
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• pp.273-278
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• 2014

We present an algorithm for surface reconstruction from the second-derivative data for free-form aspherics, which uses a subaperture scanning system that measures the local surface profile and determines the three second-derivative values at those local sampling points across the free-form surface. The three second-derivative data were integrated to get a map of x- and y-slopes, which went through a second Southwell integration step to reconstruct the surface profile. A synthetic free-form surface 200 mm in diameter was simulated. The simulation results show that the reconstruction error is 19 nm RMS residual difference. Finally, the sensitivity to noise is diagnosed for second-derivative Gaussian random noise with a signal to noise ratio (SNR) of 16, the simulation results proving that the suggested method is robust to noise.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.21-32
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• 2017

The objective of this study is to analysis the mechanical characteristics on the geometric nonlinear behavior of radial cable roof systems for long span retractable cable roof structures. The retractable roof is designed as a full control system to overcome extreme outdoor environments such as extreme hot or cold weather, strong wind or sunlight, and the cable roof greatly can reduce roof weight compared to other rigid structural system. A retractable cable roof system is a type of structures in which the part of entire roof can be opened and closed. The radial cable roof is an effective structural system for large span retractable roofs, the outer perimeter of the roof is a fixed membrane roof and the middle part is a roof that can be opened and closed. The double arrangement cables of a radial cable truss roof system with reverse curvature works more effectively as a load bearing cables, the cable system can carry vertical load in up and downward direction. In this paper, to analyze the mechanical characteristics of a radial cable roof system with central posts, the authors will investigate the tensile forces of bearing cables, stabilized cables, ring cables, and the deflection of roof according to the height of the post or hub that affects the sag ratio of cable truss. The tensile forces of the cables and the deflection of the roof are compared for the cases when the retractable roof is closed and opened.

• Korean Medical Education Review
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• v.9 no.2
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• pp.29-40
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• 2007

Purpose: This study analysed the intention of medical students career choice, educational programmes, and mentoring and counseling system for career planning at Yonsei medical school in Korea. Methods: The data were collected based on four separate graduation questionnaires at Yonsei medical school in the years of 2005, 2006, 2007, and 2008. The number of the survey was 130 in 2005, 130 in 2006, 153 in 2007, and that of the latest was 120 in 2008. We analysed the career intention on medical specialties and activities, and perceptions of important factors in choosing medical specialty. Results : The results which can be drawn from this study are these: firstly. students had more intention for choosing clinical medicine as university faculty than any other activities. While male students preferred to major in surgery, neurosurgery, orthopedic surgery, urology, otorhinolaryngology, female students in internal medicine, neurology, anesthesiology and pain medicine, diagnostic radiology, laboratory medicine. Secondly, students perceived that the most important factor which can influence on choosing a medical specialty was individual factor such as one's interests and concerns, values, and aptitudes. In stead, they relatively less perceived mentor and role model's effects on choosing a medical specialty compared to those of the United States of America. Third, the career planning at Yonsei medical school was evaluated well, especially educational programmes for career planning such as self assessment programme, elective(specialized) courses, and conversation with a senior programme. Conclusions: Unexpectedly, there are high demands for career planning by medical students. Therefore, we will reorganize systematic devices for career planning such as mentoring and counseling system at medical school.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.125-133
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• 2008

Achieving consistent geometric design is an important goal in highway design to ensure obtaining safe, economical and smooth traffic operation. Most evaluation of consistency is based on 'speed change' in speed profile. According to literature, the speed depends on geometric elements, speed on tangent section prior to a curve, and background around roads. Especially, the radius is the most main element mentioned in various literature. Therefore, this paper shows two ways of calculating horizontal radius on real road, that is, three-dimensional road. First of all, the radius of horizontal curve is calculated based on physical method. The calculated radius contains not only superelevation but also longitudinal grade while the current minimum radius is calculated by considering superelevation and side friction according to the point-mass equation. Secondly, the problem of composed curves with distorted appearance by overlaying sag or crest vertical alignment has been known. To quantify the extent of distortion effects, the method of calculation of real seen so called 'Perspective Radius' is developed. The paper presents the perspective radius and recommended perspective radius.