• Title/Summary/Keyword: HURDLES

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Influence of failed blade-pitch-control system to FOWT by aero-elastic-control-floater-mooring coupled dynamic analysis

  • Bae, Yoon Hyeok;Kim, Moo-Hyun
    • Ocean Systems Engineering
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    • v.3 no.4
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    • pp.295-307
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    • 2013
  • More FOWTs (floating offshore wind turbines) will be installed as relevant regulations and technological hurdles are removed in the coming years. In the present study, a numerical prediction tool has been developed for the fully coupled dynamic analysis of FOWTs in time domain including aero-loading, tower elasticity, blade-rotor dynamics and control, mooring dynamics, and platform motions so that the influence of rotor-control dynamics on the hull-mooring performance and vice versa can be assessed. The developed coupled analysis program is applied to Hywind spar design with 5 MW turbine. In case of spar-type floaters, the control strategy significantly influences the hull and mooring dynamics. If one of the control systems fails, the entire dynamic responses of FOWT can be significantly different. Therefore, it is important to maintain various control systems in a good operational condition. In this regard, the effects of failed blade pitch control system on FOWT performance including structural and dynamic responses of blades, tower, and floater are systematically investigated. Through this study, it is seen that the failure of one of the blade pitch control system can induce significant dynamic loadings on the other blades and the entire FOWT system. The developed technology and numerical tool are readily applicable to any types of floating wind farms in any combinations of irregular waves, dynamic winds, and steady currents.

Structure-Based Virtual Screening of Protein Tyrosine Phosphatase Inhibitors: Significance, Challenges, and Solutions

  • Reddy, Rallabandi Harikrishna;Kim, Hackyoung;Cha, Seungbin;Lee, Bongsoo;Kim, Young Jun
    • Journal of Microbiology and Biotechnology
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    • v.27 no.5
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    • pp.878-895
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    • 2017
  • Phosphorylation, a critical mechanism in biological systems, is estimated to be indispensable for about 30% of key biological activities, such as cell cycle progression, migration, and division. It is synergistically balanced by kinases and phosphatases, and any deviation from this balance leads to disease conditions. Pathway or biological activity-based abnormalities in phosphorylation and the type of involved phosphatase influence the outcome, and cause diverse diseases ranging from diabetes, rheumatoid arthritis, and numerous cancers. Protein tyrosine phosphatases (PTPs) are of prime importance in the process of dephosphorylation and catalyze several biological functions. Abnormal PTP activities are reported to result in several human diseases. Consequently, there is an increased demand for potential PTP inhibitory small molecules. Several strategies in structure-based drug designing techniques for potential inhibitory small molecules of PTPs have been explored along with traditional drug designing methods in order to overcome the hurdles in PTP inhibitor discovery. In this review, we discuss druggable PTPs and structure-based virtual screening efforts for successful PTP inhibitor design.

Molecular Diagnosis for Personalized Target Therapy in Gastric Cancer

  • Cho, Jae Yong
    • Journal of Gastric Cancer
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    • v.13 no.3
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    • pp.129-135
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    • 2013
  • Gastric cancer is the second leading cause of cancer-related deaths worldwide. In advanced and metastatic gastric cancer, the conventional chemotherapy with limited efficacy shows an overall survival period of about 10 months. Patient specific and effective treatments known as personalized cancer therapy is of significant importance. Advances in high-throughput technologies such as microarray and next generation sequencing for genes, protein expression profiles and oncogenic signaling pathways have reinforced the discovery of treatment targets and personalized treatments. However, there are numerous challenges from cancer target discoveries to practical clinical benefits. Although there is a flood of biomarkers and target agents, only a minority of patients are tested and treated accordingly. Numerous molecular target agents have been under investigation for gastric cancer. Currently, targets for gastric cancer include the epidermal growth factor receptor family, mesenchymal-epithelial transition factor axis, and the phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin pathways. Deeper insights of molecular characteristics for gastric cancer has enabled the molecular classification of gastric cancer, the diagnosis of gastric cancer, the prediction of prognosis, the recognition of gastric cancer driver genes, and the discovery of potential therapeutic targets. Not only have we deeper insights for the molecular diversity of gastric cancer, but we have also prospected both affirmative potentials and hurdles to molecular diagnostics. New paradigm of transdisciplinary team science, which is composed of innovative explorations and clinical investigations of oncologists, geneticists, pathologists, biologists, and bio-informaticians, is mandatory to recognize personalized target therapy.

A STUDY ON FLOW IN A SLIT NOZZLE FOR DISPENSING A LOW-VISCOSITY SOLUTION OF SINGLE-WALLED CARBON NANOTUBES (저점성 SWNT 분산액 도포용 슬릿 노즐 설계를 위한 유동해석)

  • Shon, B.C;Kwak, H.S.;Lee, S.H.
    • Journal of computational fluids engineering
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    • v.14 no.1
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    • pp.78-85
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    • 2009
  • A combined theoretical and numerical study is conducted to design a slit nozzle for large-area liquid coating. The objectives are to guarantee the uniformity in the injected flow and to provide the capability of explicit control of flow rate. The woking fluid is a dilute aqueous solution containing single-walled carbon nanotubes and its low viscosity and the presence of dispersed materials pose technical hurdles. A theoretical analysis leads to a guideline for the geometric design of a slit nozzle. The CFD-based numerical experiment is employed as a verification tool. A new flow passage unit, connected to the nozzle chamber, is proposed to permit the control of flow rate by using the commodity pressurizer. The numerical results confirm the feasibility of this idea. The optimal geometry of internal structure of the nozzle has been searched for numerically and the related issues are discussed.

Outage Probability for Cooperative Nano Communication in the THz Gap Frequency Range

  • Samarasekera, A. Chaminda J.;Shin, Hyundong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.1
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    • pp.102-122
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    • 2017
  • Nanotechnology has provided a set of tools that the engineers can use to design and manufacture integrated nano devices, which are capable of performing sensing, computing, data storing and actuation. One of the main hurdles for nano devices has been the amount of power that it can generate for transmission of data. In this paper, we proposed cooperative nano communication in the Terahertz (THz) Gap frequency band to increase the range of transmission. Outage probability (OP) performances for the proposed cooperative nano communication networks in the THz band (0.1 - 10THz) have been evaluated for the following scenarios; A) A single decode-and-forward (DF) relay over independent identically distributed (i.i.d.) Rayleigh fading channels, B) DF multi-relay network with best relay selection (BRS) over i.i.d. Rayleigh fading channels, and C) DF multi-relay network with multiple hops with BRS over i.i.d. Rayleigh fading channels. The results show that the transmission distance can be improved significantly by employing DF relays. Also, it is shown that by increasing the number of hops in a relay the OP performance is marginally degraded. The analytical results have been verified by Monte-Carlo simulation.

The Biomechanical Analysis of the First Hurdling in Men's 110m Hurdle between Skilled and Less-Skilled Hurdle Players (110 m 허들경기의 제 1허들에 대한 우수선수와 비우수선수의 운동역학적 요인 비교)

  • Gil, Ho-Jong;Yoon, Sukhoon
    • Korean Journal of Applied Biomechanics
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    • v.23 no.1
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    • pp.11-17
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    • 2013
  • The purpose of this study was to provide a fundamental information for enhancing 110m hurdlers' performance through conducting comparative biomechanical analysis between Skilled Group(SG) and Less-Skilled Group(LSG) those who are not in the first section of 110m hurdles. To persue the purpose of this study, total of 10 hurdlers participated. Then they were divided into two groups; SG: five hurdlers who have won awards with 14-second range at 2010 national track and field event, and LSG: five hudlers who did not win any awards with 15-second range. Three-dimensional motion analysis with 12 infrared cameras(Oqus 300, Qualisys) and 1 force plate(Type 9286AA, Kistler) was performed. From this study following conclusions were obtained. 1) For the overall runtime, SG revealed faster elapsed time than that of LSG. 2) At E4, LSG showed greater trunk angle than that of SG. 3) At E3 LSG revealed higher angular velocities than that of SG. 4) No significant differences was found for AP GRF between groups but LSG showed greater VGRF than that of SG.

Quantitative analysis using decreasing amounts of genomic DNA to assess the performance of the oligo CGH microarray

  • Song Sunny;Lazar Vladimir;Witte Anniek De;Ilsley Diane
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2006.02a
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    • pp.71-76
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    • 2006
  • Comparative genomic hybridization (CGH) is a technique for studying chromosomal changes in cancer. As cancerous cells multiply, they can undergo dramatic chromosomal changes, including chromosome loss, duplication, and the translocation of DNA from one chromosome to another. Chromosome aberrations have previously been detected using optical imaging of whole chromosomes, a technique with limited sensitivity, resolution, quantification, and throughput. Efforts in recent years to use microarrays to overcome these limitations have been hampered by inadequate sensitivity, specificity and flexibility of the microarray systems. The oligonucleotide CGH microarray system overcomes several scientific hurdles that have impeded comparative genomic studies of cancer. This new system can reliably detect single copy deletions in chromosomes. The system includes a whole human genome microarray, reagents for sample preparation, an optimized microarray processing protocol, and software for data analysis and visualization. In this study, we determined the sensitivity, accuracy and reproducibility of the new system. Using this assay, we find that the performance of the complete system was maintained over a range of input genomic DNA from 5 ug down to 0.15 ug.

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Development of flexible 3.5' QCIF (176 X144 pixels) OTFT driven OLED;Integration technologies compatible with normal semiconductor processes

  • Kang, Seung-Youl;Ahn, Seong Deok;Oh, Ji-Young;Kim, Gi-Hyun;Koo, Jae Bon;You, In-Kyu;Kim, Chul-Am;Hwang, Chi-Sun;KoPark, Sang-Hee;Yang, Yong-Suk;Chung, Sung-Mook;Lee, Jeong-Ik;Chu, Hye-Yong;Suh, Kyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.62-65
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    • 2007
  • Conventional semiconductor processes have been utilized to fabricate 3.5-inch OTFT-driven OLEDs with a resolution of $176\;{\times}\;144$ pixels on plastic substrates. By using a PC-OVD method to deposit a pentacene layer and optimizing patterning and the following processes, we could complete a uniform and reliable integration procedure for an active matrix organic light emitting devices on a plastic substrate. The technical importance of ours is the applicability of conventional semiconductor process to organic materials on plastic substrates. Although there are many hurdles to overcome, our approach and technical improvements are proved to be applicable to plastic electronics.

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FACTORS AFFECTING THE SUCCESS/FAILURE OF ROAD INFRASTRUCTURE PROJECTS UNDER PPP IN INDIA

  • Nallathiga, Ramakrishna;Shaikh, Haris D;Shaikh, Tauseef F;Sheik, Farhan A
    • Journal of Construction Engineering and Project Management
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    • v.7 no.4
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    • pp.1-12
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    • 2017
  • India has accorded a high priority to road infrastructure development through Public-Private Partnership (PPP) and it has set a high target for investment inflows. Yet, it is widely held that road/highway infrastructure has not been developing at required pace and that the road infrastructure projects under PPP have been suffering from several hurdles and delays, thereby affecting project success/failure. This paper is an attempt to analyze the critical success/failure factors of road infrastructure projects under PPP in India. A questionnaire survey was conducted among a sample of the stakeholders of road infrastructure projects to identify the critical success/failure factors during all four major project stages using different approaches. Initially, the critical factors were identified through ranking based on the average/mean score. Later, the conventional RII score was used to identify the critical success/failure factors. Finally, the critical success/failure factors were also identified based on the stakeholder-wise ranking of the factors and their convergence. The assessment revealed that there was a greater convergence across the different methods and also that there was greater consensus among project stakeholder on the critical success/failure factors of road PPP projects.

Performance Analysis of Men's 110-m Hurdles using Rhythmic Units

  • Hong, Sung Hong;Ryu, Jae Kyun
    • Korean Journal of Applied Biomechanics
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    • v.28 no.2
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    • pp.79-85
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    • 2018
  • Objective: This study aimed to create a strategic training method to enhance optimal athletic ability using information from 1H to 10H rhythmic units. Method: Top three world class athletes and three national winners of 110-m hurdle finals from the 2010 Daegu International Athletics Competition and 2017 National Athletics Championship, respectively, were selected. To analyze the kinematic variables, Dartfish 9.0 was used for two-dimensional analysis. Results: Regarding the interval time from the start to the finish line, the national athletes took less time during the pure acceleration phase (start to 1H) than the foreign athletes. The horizontal velocity increase was slower after 1H; the national athletes showed a lack of ability to accelerate at the interval phases. Moreover, the hurdle clearance time between phases was longer in the national athletes than in the foreign athletes and lacked consistency. Conclusion: The national athletes lacked the ability to accelerate at the transition, maximum rhythm, rhythm maintenance, and re-acceleration phases and showed a longer hurdle clearance time. If technical improvements and strategic training methods using rhythmic units are applied for hurdling motions, the national athlete's hurdling abilities, performance, and consistency could improve.