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Comparison of Hilbert and Hilbert-Huang Transform for The Early Fault Detection by using Acoustic Emission Signal (AE 신호를 이용한 조기 결함 검출을 위한 Hilbert 변환과 Hilbert-Huang 변환의 비교)

  • Gu, Dong-Sik;Lee, Jong-Myeong;Lee, Jung-Hoon;Ha, Jung-Min;Choi, Byeong-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.2
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    • pp.258-266
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    • 2012
  • Recently, Acoustic Emission (AE) technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the rolling element bearing problems and Wavelet transform is a powerful method to detect faults occurred on gearboxes. However, exact method for AE signal is not developed yet. Therefore, in this paper, two methods, which is Hilbert transforms (HT) and Hilbert-Huang transforms (HHT), will be compared for development a signal processing method for early fault detection system by using AE. AE signals were measured through a fatigue test. HHT has better advantages than HT because HHT can show the time-frequency domain result. But, HHT needs long time to process a signal, which has a lot of data, and has a disadvantage in de-noising filter.

France's Cluster Policy: the Competitiveness Pole (프랑스의 산업클러스터 정책 -경쟁거점($P{\hat{o}}le$ de $Comp{\acute{e}}titivit{\acute{e}}$)을 중심으로)

  • Jeong, Ok-Ju
    • Journal of the Korean association of regional geographers
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    • v.12 no.6
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    • pp.704-719
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    • 2006
  • The study deals with the France's recent cluster policy represented by the Competitiveness Pole. As a national level cluster supporting policy driven by the central government, the Competitiveness Pole, called 'French cluster model', :is competitiveness-oriented, and principally based on three main factors: partnerships, R&D projects and international visibility. The Competitiveness Pole is also the fruit or a long time effort to establish a decentralized governance system, and it has a lot for Korea to benchmark its relevant policies. After reviewing the Local Production System that was put in place before the Competitiveness Pole, the study treats main aspects or Competitiveness Pole policy. It analyze, then, the significance or the policy in the trend or the overall territorial policy or the country. Lastly, the study provides some implications for Korean policies such as industrial clusters, the Enterprise City and Innovation City.

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Influence of viscous effects on numerical prediction of motions of SWATH vessels in waves

  • Brizzolara, Stefano;Bonfiglio, Luca;Medeiros, Joao Seixas De
    • Ocean Systems Engineering
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    • v.3 no.3
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    • pp.219-236
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    • 2013
  • The accurate prediction of motion in waves of a marine vehicle is essential to assess the maximum sea state vs. operational requirements. This is particularly true for small crafts, such as Autonomous Surface Vessels (ASV). Two different numerical methods to predict motions of a SWATH-ASV are considered: an inviscid strip theory initially developed at MIT for catamarans and then adapted for SWATHs and new a hybrid strip theory, based on the numerical solution of the radiation forces by an unsteady viscous, non-linear free surface flow solver. Motion predictions obtained by the viscous flow method are critically discussed against those obtained by potential flow strip theory. Effects of viscosity are analyzed by comparison of sectional added mass and damping calculated at different frequencies and for different sections, RAOs and motions response in irregular waves at zero speed. Some relevant conclusions can be drawn from this study: influence of viscosity is definitely non negligible for SWATH vessels like the one presented: amplitude of the pitch and heave motions predicted at the resonance frequency differ of 20% respectively and 50%; in this respect, the hybrid method with fully non-linear, viscous free surface calculation of the radiation forces turns out to be a very valuable tool to improve the accuracy of traditional strip theories, without the burden of long computational times requested by fully viscous time domain three dimensional simulations.

Clinical Study of Nimotuzumab Combined with Chemotherapy in the Treatment of Late Stage Gastric Cancer

  • Xu, Chong-De
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10273-10276
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    • 2015
  • Objective: To explore the clinical effects of nimotuzumab combined with chemotherapy in the treatment of late gastric cancer. Methods: A total of 34 reoccurrence or metastatic patients with late stage gastric cancer who were confirmed by histopathology and/or cytology were selected and randomly divided into observational and control groups, of 17 cases each. Patients in the control group were treated with the standard DCF plan, while patients in observational group additionally received nimotuzumab. The short-term and long-term efficacy and adverse reactions in the 2 groups were followed. Results: The objective response rate (ORR) and disease control rate (DCR) were 64.7% (11/17) and 82.4% (14/17) in observational group and 25.0%(4/16) and 37.5%(6/16) in the control group(ORR and DCR between 2 groups, ${\chi}^2=5.2412$, P=0.0221 and ${\chi}^2=6.9453$, P=0.0084). The median progression-free survival (PFS) time and median overall survival (OS) time were 6.50 months and 12.50 months in observational group and 4.50 months and 8.25 months in the control group (P=0.0212; P=0.0255). The main toxic and side effects in the 2 groups were reduced leukocytes and hemoglobin, gastrointestinal reactions and hair loss and these were relieved after symptomatic treatment and nutrition support therapy. There were no differences in the occurrence of toxic and side effects between the 2 groups. Conclusions: Nimotuzumab combined with DCF plan is effective in treating late stage gastric cancer. A larger scale study is now warranted for confirmation of the findings.

First Record of Six Marine Ciliate Species of Genus Strombidium (Ciliophora: Spirotricha: Oligotrichia) from Korea with Ecological Notes

  • Lee, Eun-Sun;Xu, Dapeng;Shin, Mann-Kyoon;Kim, Young-Ok
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.3
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    • pp.192-207
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    • 2012
  • To supply the morphological and ecological information of oligotrich ciliates in Korea, water samples were seasonally collected in Gwangyang Bay and Jinhae Bay from August, 2010 to February, 2012 and processed by quantitative protargol staining method. As a result, six species belonging to the genus Strombidium Clapar$\grave{e}$de and Lachmann, 1859 are identified: Strombidium emergens Kahl, 1932; S. dalum Lynn et al., 1988; S. epidemum Lynn et al., 1988; S. tressum Lynn et al., 1988; S. bilobum Lynn and Gilron, 1993; S. pollostomum Lynn and Gilron, 1993. These six species were newly reported from Korean coastal waters. Strombidium emergens is a middle sized Strombidium ($20-50{\mu}m$ in length) and has open and deep oral groove to girdle portion. Strombidium dalum is a small sized Strombidium (${\geq}20{\mu}m$ in length), that has torch-like spiral anterior membranelles and an inverted triangles-shaped macronucleus on the posterior pole. The small sized S. epidemum has conspicuous trichites surrounding the girdle portion and ventral membranelles distinctly separated from anterior membranelles. The small sized S. tressum has torch-like spiral and extremely long trichites among the cilia of anterior membranelles. The middle sized S. bilobum has a bilobed macronucleus. Strombidium pollostomum is also a small sized Strombidium but its ventral membranelles are continuously connected with anterior membranelles. The five species except S. emergens occurred frequently over the wide range of water temperatures and salinities.

Location Decisions of Startups and Dynamics of Cluster Growth (기업가의 창업위치선택과 클러스터의 성장동력: 바이오벤처의 창업을 중심으로)

  • Sohn, Dong-Won
    • Journal of Technology Innovation
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    • v.17 no.1
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    • pp.69-95
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    • 2009
  • This paper examines the motives for location decisions of startups and dynamics of cluster growth. Because the location decision is intrinsically strategic choice by entrepreneurs, it is an interplay of three critical forces; cost-benefit of the choice, R&D ability of new entrants, and R&D capability of incumbents in clusters. The effect of knowledge spillovers influences the cluster growth like a double-edge sword; both a positive effect of technology learning and a negative effect of knowledge de-learning. Using data on 710 bio-tech venture firms in Korea, this paper tests the hypotheses about the factors influencing the growth of the cluster. The empirical analyses suggested that early entrepreneurial activity in the clustered regions were important, however other factors such as the organizational legacy, internal dynamics inside a cluster, and the existence of cooperation norm in the cluster, affected long term viability of the cluster.

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Multi-focus 3D display of see-through Head-Mounted Display type (투시형 두부 장착형 디스플레이방식의 다초점 3차원 디스플레이)

  • Kim, Dong-Wook;Yoon, Seon-Kyu;Kim, Sung-Kyu
    • Journal of Broadcast Engineering
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    • v.11 no.4 s.33
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    • pp.441-447
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    • 2006
  • See-through HMD type 3D display can provide an advantage of us seeing virtual 3D data used stereoscopic display simultaneously with real object(MR-Mixed Reality). But, when user sees stereoscopic display for a long time, not only eye fatigue phenomenon happens but also de-focus phenomenon of data happens by fixed focal point of virtual data. Dissatisfaction of focus adjustment of eye can be considered as the important reason of this phenomenon. In this paper, We proposed an application of multi-focus in see-through HMD as a solution of this problem. As a result, we confirmed that the focus adjustment coincide between the object of real world and the virtual data by multi-focus in monocular condition.

A Study on the Web Service Quality and User Satisfaction at Open Market (오픈마켓의 웹서비스 품질과 사용자 만족)

  • Son, Yong-Shim;Seo, Chang-Gab
    • Journal of Digital Convergence
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    • v.11 no.6
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    • pp.113-127
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    • 2013
  • The open market are expanding service quality which was used as rating scale in the field of marketing. In accordance with open market, they convert it to e-service quality and use it. Udo et al.[6] suggested web service quality combining e-SEVQUAL[2] and extended Information Success Model[7]. This study suggests four influence factors of e-service quality in the open market; website privacy and security, web site contents, web site convenience, and images of the open market companies. The study conducted survey on 301 college students and life long education center students in Busan. The study found that all four influence factors have positive effects on the web service quality and ultimately web service quality has beneficial effects on the satisfaction in open market users' information system.

A Study on Workers' Exposure to Organic Solvents in Petroleum Refinery (원유정제업 작업자들의 유기용제에 대한 노출 평가)

  • Choi, Sang Jun;Paik, Nam Won;Kim, Jin Kyoung;Choi, Yeon Ki;Jung, Hyun Hee;Heo, Sung-Min
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.1
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    • pp.27-35
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    • 2005
  • This study was carried out to evaluate the characteristics of petroleum refinery workers' exposure to organic solvents. Exposure assessment was conducted by full shift-based long term personal sampling(TWA-P) and task-based short term personal sampling(STEL-P) strategy. Major organic solvents that workers can be exposed are various, varying from C3~C12, and this study focused on 11 kinds including benzene, considering toxicity and concentration level. In comparison with two sampling results, STEL-P shows a significant(p<0.001) excess of exposure level rather than TWA-P. As the potential risk index for benzene is calculated as 16, benzene should be set the highest priority for control in petroleum refinery industry. The tasks with the highest benzene exposure level were de-watering(AM;99.8 ppm), draining(AM;19.6ppm), sampling(AM;16.2ppm), and manual gauging(AM;15.02ppm). Petroleum refinery workers' exposure pattern to organic solvents differs by tasks performed, and some task has a high risk of temporary extreme exposure. Therefore, traditional 8-hour TWA sampling strategy have possibility of underestimation of exposure level of workers in petroleum refinery.

The Comparative Study of Koanbok between the koryo and Sung Dynasty (고려시대와 송대의 관복 비교연구 - 공.상복을 중심으로 -)

  • 서옥경
    • Journal of the Korean Society of Costume
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    • v.31
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    • pp.131-144
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    • 1997
  • This thesis is mainly on the study of Gongbok and Sangbok in the system of official outfit of the Koryo dyn-asty which has not yet fully studied in the history of Koren dress and its ornaments. Even in this difficult circumstances the sys-tem of dress and its ornaments can be under-stood with the help of remaining Buddhi-stliterature. Thus the system of official outfit in the Koryo dynasty has been studied here with some documentary records such as Koryo-dokyung Koryosa-yeobokji (The His-tory of Dress And Its Ornaments in The Koryo Dynasty) and so on. As the Koryo dynasty de-veloped her international relationships continu-ously with her neighbouring nation which were geographically closely connected so the systems of official outfit in the Chinese dyn-asty of Sung had to be studied and compared with, In the Koryo dynasty the same four colour system of purple red, deep red and green had survived until the year of 1123 from the year of 960 not using the blue colour from the four colour system of purple Chinese red green and blue of the Sung dynasty. The four colour system of purple deep red green and black under the regin of the King Euijong was exactly the same as that of official outfit of the Sung dynasty in he year of 1078 the first year of Wonpung's regin and wearing Eodae is a sure sign of influence of the system of Sung dynasty. Even though Koryo was invaded by Yuan druing the period of the regin of the King Chungyul the four colour system was not changed of purple deep red. green and black along with the same Dae-sudanryung(long sleeve and round collar). In 1387 the thirteenth year of the King Woo of the Koryo dynasty Pumdae was used ofor different official ranks and the sys-tem of wearing Samo and Dayung was established for the official outfit of every government officers.

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