• Title/Summary/Keyword: incoherent

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A Study on Propeller Noise Localizations in a Cavitation Tunnel Using MFP (정합장 처리를 이용한 캐비테이션 터널에서의 프로펠러 소음원 위치 추적에 관한 연구)

  • Park, Cheol-Soo;Cho, Yong-Jin;Seol, Han-Shin
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.5
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    • pp.220-226
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    • 2007
  • The two major objectives of acoustical measurements in a cavitation tunnel are measuring the noise levels generated by rotating propellers behind a hull and localizing possible noise sources in order to reduce noise levels. Propeller noise measurement experiments were performed in MOERI cavitation tunnel at December, 2006. In order to put the propeller into cavitating conditions, a wake-generating dummy body was devised. In addition, ten hydrophones are put inside a wing-shaped casing in order to minimize the unexpected flow induced self noise around hydrophone itself. After measuring both of the noises of the rotating propeller behind the dummy body and signals generated by a virtual source, respectively the data were matched field processed using the frequency incoherent Bartlett processor to localize noises on the propeller plane. In this paper, we presented the measured noise analysis and the localization results.

Change of the Time Use Pattern by Internet Use: Analysis on the Korean Time Use Survey (2000, 2005) (인터넷 이용에 따른 생활시간 패턴의 변화: 2000년, 2005년 생활시간 조사를 활용한 통시적 분석)

  • Kang, Nam-Jun;Lee, Jae-Hyun;Oh, Hyun-Kyung
    • Korean journal of communication and information
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    • v.41
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    • pp.145-180
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    • 2008
  • This study tries to test time reallocation hypothesis proposed by Lee(2005) that claims the time use pattern as a whole has changed as new media is introduced-in this case, internet-in our daily lift. It has been pointed out that researches, confined to study whether time use for traditional media is displaced by a new media, have such a limitation as 'media isolationism' and resulted in incoherent conclusions. In order to verify time reallocation hypothesis, which explains the influence of internet use on daily activities with broad perspectives, this research employed two different methods. First, this study analyzed the differences of time use patterns of daily activities and media use behaviors between internet users and non-users by using t-test. Second, logistic regression was used to confirm that the difference of time use pattern between internet users and non-users in many daily activities. The results show that time use pattern for daily activities has reorganized In the most of the age groups. Especially, in the young age groups, time reallocation by internet appeared more obvious than the equivalent old age groups.

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Recognition and Enforcement of Foreign Arbitral Awards in Japan: Conventions, National law and Refusal of Recognition and Enforcement (일본법상 외국중재판정의 승인집행 -적용법규와 승인집행거부를 중심으로-)

  • Kim, Eon-Suk
    • Journal of Arbitration Studies
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    • v.20 no.3
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    • pp.25-46
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    • 2010
  • In spite of great interest and recent innovation of the legislative system in the Arbitration and other Alternative Dispute Resolution(ADR) system, In Japan there have been only a few case in which International commercial dispute was settled through the Arbitration compared to other countries. However, we can easily expect that foreign arbitral awards which need to be recognized and enforced in Japan will gradually increase and this makes it very important for us to review the Japanese legislative system regarding recognition and enforcement of foreign arbitral awards. In this paper, I focused on the relations between applicable laws(including convention) regarding recognition and enforcement of foreign arbitral awards in Japan and some issues concerning refusal of recognition and enforcement of foreign arbitral awards. Japan is a member state of several multilateral conventions concerning recognition and enforcement of foreign arbitral awards including the New York Convention of 1958 and at least 20 bilateral agreements which include provisions in relate to the recognition and enforcement of arbitral awards. Therefore there are some legal issues about the priority application between multilateral and bilateral agreements in relate to Article 7(1) of the New York Convention. In Japan, as I mentioned in this paper, there are incoherent opinions concerning this issue. To solve it substantially it would seem appropriate to build up concrete and explicit provisions concerning the application of priority between multilateral and bilateral agreements. On the other hand, in relate to the application between the New York Convention and National Law, it is necessary to take general approach regarding the priority application between Convention (Treaty) and National Law, considering the national application of conventions under the Constitutional System of each country. Among the grounds for non-recognition/enforcement, there are the ones that are decided under the law of the requested country, for instance, arbitrability and public policy. It would therefore be possible that some foreign arbitral awards would not be recognized in Japan especially relating to the arbitrability because its scope in Japan is not so large. Regarding the enforcement of awards annulled in their place of origin, some positive opinions in recent Japanese legal discussions, say that annulled awards should be enforced as a counter strategy of developed countries and judiciary discretion of the requested country would be needed. As mentioned in this paper, the recognition and enforcement of foreign arbitral awards is closely related to judicial policy of the requested country as the recognition and enforcement of foreign judgment is. Even though there existed uniform rules on recognition and enforcement of foreign arbitral awards like the New York convention, each country has different internal legal status of conventions under its own Constitutional System and tends to interpret the provisions based in its own profit. Therefore, it is necessary to review, in the light of conflict of laws, the national legislative system including legal status of conventions of the requested countries concerning recognition and enforcement of foreign arbitral awards.

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On the Source Identification by Using the Sound Intensity Technique in the Radiated Acoustic Field from Complicated Vibro-acoustic Sources (음향 인텐시티 기법을 이용한 복잡한 진동-음향계의 방사 음장에 대한 음원 탐색에 관하여)

  • 강승천;이정권
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.8
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    • pp.708-718
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    • 2002
  • In this paper, the problems in identifying the noise sources by using the sound intensity technique are dealt with for the general radiated near-field from vibro-acoustic sources. For this purpose, a three-dimensional model structure resembling the engine room of a car or heavy equipment is considered. Similar to the practical situations, the model contains many mutually coherent and incoherent noise sources distributed on the complicated surfaces. The sources are located on the narrow, connected, reflecting planes constructed with rigid boxes, of which a small clearance exists between the whole box structure and the reflecting bottom. The acoustic boundary element method is employed to calculate the acoustic intensity at the near-field surfaces and interior spaces. The effects of relative source phases, frequencies, and locations are investigated, from which the results are illustrated by the contour map, vector plot, and energy streamlines. It is clearly observed that the application of sound intensity technique to the reactive or reverberant field, e.g., scanning over the upper engine room as is usually practiced, can yield the detection of fake sources. For the precise result for such a field, the field reactivity should be checked a priori and the proper effort should be directed to reduce or improve the reactivity of sound field.

A Study on the Construction of Database, Online Management System, and Analysis Instrument for Biological Diversity Data (생물다양성 자료의 데이터베이스화와 온라인 관리시스템 및 분석도구 구축에 관한 연구)

  • Bec Kee-Yul;Jung Jong-Chul;Park Seon-Joo;Lee Jong-Wook
    • Journal of Environmental Science International
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    • v.14 no.12
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    • pp.1119-1127
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    • 2005
  • The management of data on biological diversity is presently complex and confusing. This study was initiated to construct a database so that such data could be stored in a data management, and analysis instrument to correct the problems inherent in the current incoherent storage methods. MySQL was used in DBMS(DataBase Management System), and the program was basically produced using Java technology Also, the program was developed so people could adapt to the requirements that are changing every minute. We hope this was accomplished by modifying easily and quickly the advanced programming technology and patterns. To this end, an effective and flexible database schema was devised to store and analyze diversity databases. Even users with no knowledge of databases should be able to access this management instrument and easily manage the database through the World Wide Web. On a basis of databases stored in this manner, it could become routinely used for various databases using this analysis instrument supplied on the World Wide Web. Supplying the derived results by using a simple table and making results visible using simple charts, researchers could easily adapt these methods to various data analyses. As the diversity data was stored in a database, not in a general file, this study makes the precise, error-free and high -quality storage in a consistent manner. The methods proposed here should also minimize the errors that might appear in each data search, data movement, or data conversion by supplying management instrumentation on the Web. Also, this study was to deduce the various results to the level we required and execute the comparative analysis without the lengthy time necessary to supply the analytical instrument with similar results as provided by various other methods of analysis. The results of this research may be summerized as follows: 1)This study suggests methods of storage by giving consistency to diversity data. 2)This study prepared a suggested foundation for comparative analysis of various data. 3)It may suggest further research, which could lead to more and better standardization of diversity data and to better methods for predicting changes in species diversity.

The Grounded Theoretical Study on Negative Emotion Recovery Process of Female College Students Through Bibliotherapy (독서치료를 통한 여대생의 부정적 정서 회복과정에 대한 근거이론적 연구)

  • Kim, Kil-Ja
    • Journal of the Korean Society for Library and Information Science
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    • v.42 no.3
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    • pp.103-131
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    • 2008
  • Today. the mental health has a great deal of impact on individuals and the society surrounding. Therefore. this research is to propose a way of bibliotherapical intercession by stages and patterns as to examine the recovery process of students with negative emotion by using the grounded theoretical method. This research collected materials through focus-interview, participant observation and book reports of 4 experiments involving female college students aged from 21 to 23, all having emotional and psychological difficulties. The recovery process of female students with negative emotion involved causal factors such as "recognition of hidden wound" "Sense of inferiority", and "difficulty in forming relationships", as well as contextual factors like "sympathetic attitude". which altogether brought about the core phenomenon. "pursuit for healthy ego". This core phenomenon induced to recovering the bright and positive attitude through using the strategies of 'self insight' and application of 'management plan', influence by such incoherent conditions as 'intimate surroundings' and $\setminus$ 'support system patterns'. And as time passed. the recovery process appeared tin four stages: 'issues recognition'. 'emotional responses', 'issue solution' and 'self application'.

Soft Plasma Flash X-ray Generator Utilizing a Vacuum Discharge Capillary

  • Sato, Eiichi;Hayasi, Yasuomi;Usuki, Tatsumi;Sato, Koetsu;Takayama, Kazuyoshi;Ido, Hideaki
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.400-403
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    • 2002
  • The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.

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Effects of Microstructure and Plate Orientation on the Acoustic Emission Behavior of an Al-Li 8090 Alloy (Al-Li 8090 합금의 미세조직과 이방성에 따른 음향방출 거동)

  • Lee, K.A.;Lee, C.S.;Jeong, H.D.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.16 no.4
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    • pp.215-224
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    • 1997
  • A study has been made to investigate the acoustic emission(AE) behavior during the tensile and fracture tests of an Al-Li 8090 alloy, and to correlate it with the deformation mechanisms as a function of microstructure and plate orientation. Mechanical tests and AE measurements were conducted on the specimens with different microstructures (the ${\delta}'$ phase dominant microstructure and the $S'+{\delta}'$ microstructure) and with different orientations (L and ST). In the ${\delta}'$ structure, continuous emissions were produced in both the L and ST oriented specimens, while only the burst emissions were observed to occur in the $S'+{\delta}'$ structure. It was inferred from the above results that continuous type emissions were mainly attributed to the shearing of coherent ${\delta}'$ precipitates in the ${\delta}'$ structure, while the burst type emissions were produced due to the shearing or microcracking of incoherent S' phase in the $S'+{\delta}'$ structure. As to the effect of plate orientation, the ST oriented specimens showed more burst emissions than the LT oriented ones. A large number of burst emissions produced in the ST specimen were presumably due to the rapid crack propagation along the intergranular boundary located parallel to the crack propagation direction.

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An Intertextual Approach to Narcissa Benbow in Sanctuary, Sartoris and "There Was a Queen" (나시서 벤보우에 관한 상호텍스트적 연구)

  • Shin, Young-Hun;Kang, Ji-Hyun
    • The Journal of the Korea Contents Association
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    • v.20 no.2
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    • pp.300-309
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    • 2020
  • Recent studies on William Faulkner's female characters have overcome much of the stereotyped and dichotomous approaches of the past by uncovering their subversive characteristics. Nevertheless, they still present some limitations in regards to analyzing the characters based on individual texts. This paper attempts an inter-textual approach to Narcissa Benbow, the central character of Sanctuary, Sartoris and "There Was a Queen." In Sanctuary, Narcissa, a young widow of a Southern aristocratic family, harshly accuses her brother Horace, a lawyer of taking a murder suspect's wife and her infant child to their old house. She is afraid that their existence could harm the reputation of her family and herself. Eventually, she kicks them out of the house. In contrast, she is described as being friendly and calm in Sartoris. In addition, in "There Was a Queen," Narcissa makes an attempt to get an obscene letter back from an FBI agent in exchange for a sexual favor in order to prevent the letter from being disclosed. This paper takes into account the possibility of seeing these incoherent or even contradictory aspects of her characterization with a consistent view. This confirms that an inter-textual approach is needed to properly understand those round female characters created by Faulkner.

High Resolution Time Resolved Contrast Enhanced MR Angiography Using k-t FOCUSS (k-t FOCUSS 알고리듬을 이용한 고분해능 4-D MR 혈관 조영 영상 기법)

  • Jung, Hong;Kim, Eung-Yeop;Ye, Jong-Chul
    • Investigative Magnetic Resonance Imaging
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    • v.14 no.1
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    • pp.10-20
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    • 2010
  • Purpose : Recently, the Recon Challenge at the 2009 ISMRM workshop on Data Sampling and Image Reconstruction at Sedona, Arizona was held to evaluate feasibility of highly accelerated acquisition of time resolved contrast enhanced MR angiography. This paper provides the step-by-step description of the winning results of k-t FOCUSS in this competition. Materials and Methods : In previous works, we proved that k-t FOCUSS algorithm successfully solves the compressed sensing problem even for less sparse cardiac cine applications. Therefore, using k-t FOCUSS, very accurate time resolved contrast enhanced MR angiography can be reconstructed. Accelerated radial trajectory data were synthetized from X-ray cerebral angiography images and provided by the organizing committee, and radiologists double blindly evaluated each reconstruction result with respect to the ground-truth data. Results : The reconstructed results at various acceleration factors demonstrate that each components of compressed sensing, such as sparsifying transform and incoherent sampling patterns, etc can have profound effects on the final reconstruction results. Conclusion : From reconstructed results, we see that the compressed sensing dynamic MR imaging algorithm, k-t FOCUSS enables high resolution time resolved contrast enhanced MR angiography.