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Two Marine Sponges of the Family Ancorinidae (Demospongiae: Astrophorida) from Korea

  • Shim, Eun Jung;Sim, Chung Ja
    • Animal Systematics, Evolution and Diversity
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    • v.29 no.1
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    • pp.31-35
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    • 2013
  • Two sponges, Stelletta subtilis (Sollas, 1886) and Stryphnus sollasi n. sp., were collected from depth of 24-30 m at Jeju-do Island and Chuja-do Island by SCUBA diving from July 2003 to June 2010. The new species Stryphnus sollasi n. sp is similar with Stryphnus niger Sollas, 1886 in the composition of spicules, however they differ in colour and spicule size. This new species has smaller oxeas and larger oxyasters than those of S. niger. This new species has two size categories of oxyaster but S. niger has one size category of oxyaster. The colour of S. sollasi n. sp is white, but the latter puce black. Stelletta subtilis (Sollas, 1886) is first recorded in Korean fauna.

Implementing an Analysis System for Housing Business Based on Seoul Apartment Price Data (주택 사업 분석 시스템 구축 : 서울지역 아파트 가격 데이터를 중심으로)

  • 김태훈;이희석;김재윤;전진오;이은식
    • The Journal of Information Technology and Database
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    • v.6 no.2
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    • pp.115-130
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    • 1999
  • The price structure of housing market varies depending upon market price policy rather than low or high price policy because of IMF. The object of this study is to develop an analysis system for analyzing housing market and its demand. The analysis system consists of four major categories: macro index analysis, market decision analysis, housing market analysis, and consumer analysis. We model each category by using a variety of techniques such as generalized linear model, categorical analysis, bubble analysis, drill-down analysis, price sensitivity meter analysis, optimum price index analysis, profit index measurement analysis, correspondence analysis, conjoint analysis, and multidimensional scaling analysis. Seoul apartment data is analyzed to demonstrate the practical usefulness of the system.

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Development of tool condition monitoring system using unsupervised learning capability of the ART2 network

  • Choii, Gi-Sang
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1570-1575
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    • 1991
  • The feasibility of using an adaptive resonance network (ART2) with unsupervised learning capability for too] wear detection in turning operations is investigated. Specifically, acoustic emission (AE) and cutting force signals were measured during machining, the multichannel AR coefficients of the two signals were calculated and then presented to the network to make a decision on tool wear. If the presented features are significantly different from previously learned patterns associated with a fresh tool, the network will recognize the difference and form a new category m worn tool. The experimental results show that tool wear can be effectively detected with or without minimum prior training using the self-organization property of the ART2 network.

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A Study on the Defect Detection of Silicon-Chip Surrounding by Ultrasonic Wave - Automatic Determination Method of Threshold Value by Image Processing - (초음파를 이용할 실리콘 칩 주위의 결함 검출에 관한 연구 - 화상처리에 의한 threshold value의 자동 결정법 -)

  • 김재열;박환규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.11a
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    • pp.87-94
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    • 1991
  • This Paper is to aim the microdefect evaluation of semiconductor Package into a quantitative from NDI's image processing of ultrasonic wave. Accordingly, for the detection of delamination between the Joining condition of boundary microdefect of semiconductor packaga the result from sampling original image, histogramming, binary image or image processing of multinumerloal value is such as the follows. ([) The least limitation from the microdefect detection of the semiconductor package by surveying high ultrasonic wave seems to be about 0.8 $\mu\textrm{m}$ in degree. (2) A result of applying the image processing of multinumerical value to the semiconductor package it was possible to devide the Category into the effectiveness.

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GRADED w-NOETHERIAN MODULES OVER GRADED RINGS

  • Wu, Xiaoying
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.5
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    • pp.1319-1334
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    • 2020
  • In this paper, we study the basic theory of the category of graded w-Noetherian modules over a graded ring R. Some elementary concepts, such as w-envelope of graded modules, graded w-Noetherian rings and so on, are introduced. It is shown that: (1) A graded domain R is graded w-Noetherian if and only if Rg𝔪 is a graded Noetherian ring for any gr-maximal w-ideal m of R, and there are only finite numbers of gr-maximal w-ideals including a for any nonzero homogeneous element a. (2) Let R be a strongly graded ring. Then R is a graded w-Noetherian ring if and only if Re is a w-Noetherian ring. (3) Let R be a graded w-Noetherian domain and let a ∈ R be a homogeneous element. Suppose 𝖕 is a minimal graded prime ideal of (a). Then the graded height of the graded prime ideal 𝖕 is at most 1.

A study of the model development of Korean Quick Response System(Part II) -Focused on the adoption situation and the factors related to the adoption- (한국형 신속대응 시스템 모델개발에 관한 연구 (제1보) -도입현황과 도입관련 요인 중심으로-)

  • 고은주;강희정
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.7
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    • pp.1052-1063
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    • 1999
  • The purpose of this study was to investigate the current development of Quick Response (QR) system and to identify factors related to QR adoption. A random sample of 250 apparel manufactures were selected from the Korean apparel manufacturers' list Response rate was 41% (m=102) A mail questionnaire was used to investigate the purpose of the study. ANOVAs and Duncan's multiple range tests were used. The results are as follows: 1. The most frequently used technologies were small lot orders and CAD and the least used technology is the electronic order system, 2. Firm size product characteristics(product category fashion change) and CEO's age were significantly related to the usage level of QR technologies.

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Nonlinear dynamic analysis by Dynamic Relaxation method

  • Rezaiee-Pajand, M.;Alamatian, J.
    • Structural Engineering and Mechanics
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    • v.28 no.5
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    • pp.549-570
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    • 2008
  • Numerical integration is an efficient approach for nonlinear dynamic analysis. In this paper, general category of the implicit integration errors will be discussed. In order to decrease the errors, Dynamic Relaxation method with modified time step (MFT) will be used. This procedure leads to an alternative algorithm which is very general and can be utilized with any implicit integration scheme. For numerical verification of the proposed technique, some single and multi degrees of freedom nonlinear dynamic systems will be analyzed. Moreover, results are compared with both exact and other available solutions. Suitable accuracy, high efficiency, simplicity, vector operations and automatic procedures are the main merits of the new algorithm in solving nonlinear dynamic problems.

A Study on the performance test of Water mist system as a fire extinguish system for Ships (선박용 미분무수 소화설비의 성능평가연구)

  • Kim, Sung-Yoon;Ahn, Bung-Ho;Kim, Dong-Seuk;Kim, You-Taek
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.155-156
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    • 2006
  • Developed and conducted a performance test of the Water mist system that is satisfied with the requirement of a fire test requiring Class 3 Engine Mock-up exceeding net volume $3,000m^3$ as per IMO's MSC/Circ. 668 Appendix B(Test method for fire testing equivalent water-based fire-extinguishing systems for machinery spaces of category A and cargo pump rooms).Even though fuel atomizing was continued for 15 sec. after stopping of the system according to the test method relating to the atomizing fire type, no fire was reignited. This result shows the excellence of the system. There was no damage to the contents of the system after the test.

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Effects of different roll angles on civil aircraft fuselage crashworthiness

  • Mou, Haolei;Du, Yuejuan;Zou, Tianchun
    • Advances in aircraft and spacecraft science
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    • v.2 no.4
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    • pp.391-401
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    • 2015
  • Crashworthiness design and certification have been and will continue to be the main concern in aviation safety. The effects of roll angles on fuselage section crashworthiness for typical civil transport category aircrafts were investigated. A fuselage section with waved-plates under cargo floor is suggested, and the finite element model of fuselage section is developed to simulate drop test subjected to 7 m/s impact velocity under conditions of 0-deg, 5-deg, 10-deg and 15-deg roll angles, respectively. A comparative analysis of failure modes, acceleration responses, and energy absorption of fuselage section under various conditions are given. The results show that the change of roll angles will significantly affect fuselage deformation, seat peak overloads, and energy absorption. The crashworthiness capability of aircraft can be effectively improved by choosing appropriate landing way.

Rotor Loss in Permanent Magnet Brushless AC Machine (고속용 영구자석모터의 손실특성)

  • Jang, S.M.;Go, J.W.;Yoon, I.K.;Lee, S.H.
    • Proceedings of the KIEE Conference
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    • 2002.04a
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    • pp.68-70
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    • 2002
  • Important category of brushless ac machine design is emerging in which the fundamental component of the stator MMF has fewer poles than the rotor. the torque being developed by a higher order MMF harmonic. The fundamental and lower order MMF harmonics can then give rise to significant rotor eddy currents. An analytical model is developed to predict rotor-induced eddy currents in such machines, and to quantify the effectiveness of circumferentially segmenting the permanent magnets in reducing the rotor loss.

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