• Title/Summary/Keyword: OoA

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Fabrication and Evaluation of Integrated Composite Part for Aircraft using OoA (Out-of-Autoclave) Prepreg (OoA (Out-of-Autoclave) 프리프레그를 이용한 항공기용 복합재 일체형 부품 제작 및 평가)

  • Hong, Sungjin;Song, Min-Hwan;Song, Keunil;Baik, Sang-Moon;Shin, Sang-Jun
    • Composites Research
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    • v.29 no.5
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    • pp.315-320
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    • 2016
  • Conventionally, composite aircraft structures are fabricated within autoclave at high pressure. However, autoclave process has several disadvantages including high curing costs and limitation of part size. Recently, out-of-autoclave (OoA) processes have been investigated in many studies to replace conventional autoclave process. A newly developed OoA prepreg, using conventional ovens, can significantly reduce the curing costs and produce autoclave-quality parts. Nevertheless, manufacture of void-free complex shape structure using OoA process presents significant challenges because of the low consolidation pressure. In this study, integrated skin-spar-rib composite part was fabricated using OoA prepreg. And cross-sectional macro- and micro-graphs of the part were examined in order to assess the possibility of replacing conventional autoclave process.

mPW1PW91 Calculated Relative Stabilities and Structures for the Conformers of 1,3-dimethoxy-p-tert-butylthiacalix[4]crown-5-ether (1,3-디메톡시-티아캘릭스[4]크라운-5-에테르의 이형체들의 상대적인 안정성과 구조들에 대한 mPW1PW91 계산 연구)

  • Kim, Kwang-ho;Choe, Jong-In
    • Journal of the Korean Chemical Society
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    • v.53 no.5
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    • pp.521-529
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    • 2009
  • Molecular structures of the various conformers for the 1,3-dimethoxy-p-tert-butylthiacalix[4] crown-5-ether (3) were optimized by using DFT B3LYP/6 - 31 + G(d,p) and mPW1PW91/6 - 31 + G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the energy differences and structures of eight in/out orientations (cone_oo, cone_oi, pc_oo, pc_io, pc_oi, pc_ii, 13a_oo, 13a_io) of two methoxy groups in three major conformations (cone, partial-cone and 1,3-alternate). The 13a_oo (out-out orientation of the 1,3-alternate conformer) is calculated to be the most stable among eight different conformations of 3, and in accord with the experimental result. The ordering of relative stability resulted from the mPW1PW91/6 - 31 + G(d,p) calculation method is following: 13a_oo > 13a_io$\sim$pc_io$\sim$cone_oo > cone_oi$\sim$pc_oo$\sim$pc_oi > pc_ii.

Evaluation of Cyst Loss in Standard Procedural Steps for Detecting of Giardia lamblia and Cryptosporidium parvum in Water

  • Kim, Kyung-Ju;Jung, Hyang-Hee;Lee, Ki-Say
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.4
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    • pp.368-371
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    • 2006
  • The standard procedure outlined by the United States Environmental Protection Agency (US EPA) in Method 1623 for analyzing Giardia lamblia cysts and Cryptosporidium parvum oocysts in water samples consists of filtration, elution, centrifugal concentration, immunomagnetic separation (IMS), and immunofluorescence assay (IFA) followed by microscopic examination. In this study, the extent of (oo)cyst loss in each step of this procedure was evaluated by comparing recovery yields in segmented analyses: (i) IMS + IFA, (ii) concentration + IMS + IFA, and (iii) filtration/elution + concentration + IMS + IFA. The complete (oo)cyst recovery by the full procedure was $52{\sim}57%$. The (oo) cyst loss in the IMS step was only $0{\sim}6%$, implying that IMS is a fairly reliable method for (oo)cyst purification. Centrifugal concentration of the eluted sample and pellet collection before IMS resulted in a loss of $8{\sim}14%$ of the (oo)cysts. The largest (oo)cyst loss occurred in the elution step, with $68{\sim}71%$ of the total loss. The permeated loss of (oo)cysts was negligible during filtration of the water sample with a $1.0-{\mu}m$ pore polyethersulfone (PES) capsule. These results demonstrated that the largest fraction of (oo)cyst loss in this procedure occurred due to poor elution from the filter matrix. Improvements in the elution methodology are therefore required to enhance the overall recovery yield and the reliability of the detection of these parasitic protozoa.

Boosting the Performance of the Predictive Model on the Imbalanced Dataset Using SVM Based Bagging and Out-of-Distribution Detection (SVM 기반 Bagging과 OoD 탐색을 활용한 제조공정의 불균형 Dataset에 대한 예측모델의 성능향상)

  • Kim, Jong Hoon;Oh, Hayoung
    • KIPS Transactions on Software and Data Engineering
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    • v.11 no.11
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    • pp.455-464
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    • 2022
  • There are two unique characteristics of the datasets from a manufacturing process. They are the severe class imbalance and lots of Out-of-Distribution samples. Some good strategies such as the oversampling over the minority class, and the down-sampling over the majority class, are well known to handle the class imbalance. In addition, SMOTE has been chosen to address the issue recently. But, Out-of-Distribution samples have been studied just with neural networks. It seems to be hardly shown that Out-of-Distribution detection is applied to the predictive model using conventional machine learning algorithms such as SVM, Random Forest and KNN. It is known that conventional machine learning algorithms are much better than neural networks in prediction performance, because neural networks are vulnerable to over-fitting and requires much bigger dataset than conventional machine learning algorithms does. So, we suggests a new approach to utilize Out-of-Distribution detection based on SVM algorithm. In addition to that, bagging technique will be adopted to improve the precision of the model.

Development of Data Object Layer (DOL) In Object-Oriented ERP Systems (객체지향 ERP 시스템에서 데이터 객체 계층의 구축)

  • Kim, Chang-Ouk;Jun, Jin
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.23 no.58
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    • pp.1-16
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    • 2000
  • To develop a generic ERP(Enterprise Resource Planning) system which can accommodate various types of manufacturing enterprises, object-oriented methods are commonly applied from analysis to implementation. The objective of OO-ERP (Object-Oriented ERP) systems is the reusability of business objects(components). In practice, one of the critical features for the reusable OO-ERP system would be the capability of interfacing with distributed, heterogeneous data repositories. Consequently, it is essential to provide data repository transparency in OO-ERP systems - business objects do not take care of the locations and types of data repositories. In this paper, we propose Data Object Layer(DOL) that supports such transparency. DOL is a horizontal component through which OO-ERP systems can be seamlessly connected with diverse data repositories.

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Out-of-Order Packet Analysis in Fast Handover for Proxy Mobile IPv6 (PMIPv6 빠른 핸드오버에서의 Out-of-Order 패킷 분석)

  • Quoc, Anh Khuong;Shon, Min Han;Choo, Hyunseung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.11a
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    • pp.287-289
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    • 2013
  • Fast Handover for Proxy Mobile IPv6 (FPMIPv6), a protocol described in RFC 5949, is used to reduce handover latency and minimize packet loss problem occuring in the Proxy Mobile IPv6 (PMIPv6) protocol. However, during the study of implementing FPMIPv6, we found the Out-of-Order Packet (OoOP) problem that occurs in the experiment of FPMIPv6. Since the OoOP is an issue that affects significantly to QoS of the network, in this paper, we analyze the OoOP problem by using network model. The analysis conducts the cause of occurring OoOP problem due to there exist two paths for data transmitted from Correspondent Node (CN) to MN in FPMIPv6.

Development of an Object-Oriented Simulator for Evaluating Object-Oriented CIM S/W (객체지향 제조관리 시스템 평가를 위한 객체지향 시뮬레이터 개발)

  • 백준걸
    • Journal of the Korea Society for Simulation
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    • v.8 no.1
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    • pp.1-18
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    • 1999
  • Current CIM systems need to correspond flexibly to the frequent change of demands of the customers and the fast changing informations about the production environment. The demands have brought forth CIM systems developed using object-oriented technology, with reusability, expansibility, and flexibility for the system components. Due to the fact that the OO-CIM system has been developed based on an incomplete data, the constructed system must be implemented to the actual surroundings to see how pertinent it is. Hence, this paper presents an OO-simulator as a means to evaluate the pertinency and the efficiency of the developed CIM system. The OO-simulator can determine the problems likely to occur when a developed CIM system is implemented to the actual site and evaluate the efficiency beforehand. Such properties will decrease the cost of CIM system development and increase the reliability of the system. This paper presents a framework for an OO-simulator composed of a virtual factory component embodying the characteristics of a virtual factory, a connector component for the interface between the CIM system and the simulator, a configuration component for modeling the constituent structure of the CIM system, and a timer component in charge of the time advance for the simulation.

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Metrics Measuring a Quality based on Object-Oriented Design Characteristics (객체지향 설계의 특성을 고려한 품질 평가 메트릭스)

  • Kim, Yu-Kyung;Park, Jai-Nyun
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.2
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    • pp.373-384
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    • 2000
  • There are many researches about metrics to measure a quality of Object-Oriented(OO) software. However, most of them have only discussed a concept or properties of metrics, and have not shown the detailed procedure for measuring them. They also define a measurement indicator as a threshold, but it has been influenced on a project size or application domains. In this paper, we propose metrics based on characteristics of OO design such as size, complexity, coupling and cohesion, and use a propotion to an average as the measurement indicator. It is easy to classify classes which have a result above the average, and to predict classes which reduced the quality of OO design. They will be modified to hold the average. Proposed metrics are analytically evaluated by Weyuker's nine properties. They are satisfied with seven properties except two properties co not apply to OO metrics. Also, we design a quality assessment system, ASSOD(ASsessment System of Object oriented Design), to measure the quality of the OO design independent of the platform.

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Effects of Soyoligosaccharides on Blood glucose and Lipid Metabolism in Streptozotocin-Induced Diabetic Rats (대두올리고당이 당뇨 유발 흰쥐의 혈당 및 지질대상에 미치는 영향)

  • 김미현;김혜영;김우경;김지영;김숙희
    • Journal of Nutrition and Health
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    • v.34 no.1
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    • pp.3-13
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    • 2001
  • This study was conducted to investigate the effect of soyligosaccharides on improvement of diabetes mellitus. Sprague Dawley rats were divided into three groups. Control and one experimental group were fel AIN-93G diet(mixed diet) and the other experimental group was fed a similar diet containing 5% soyligosaccharides(oligosaccharide diet) for 6 weeks. Experimental groups were divided into two sub-groups after streptozotocin(STZ) injection and fed th mixed diet or the oligosaccharide diet for the next 2 weeks. Followings are final experimental and control groups: MM (mixed dietlongrightarrowSTZ injectionlongrightarrowmixed diet). MO(mixed dietlongrightarrowSTZ injectionlongrightarrowoligosaccharide diet), OM( oligosaccharide dietlongrightarrowSTZ injectionlongrightarrowmixed diet), OO(oligosaccharide dietlongrightarrowSTZ injectionlongrightarrowoligosaccharide diet), C(mixed dietlongrightarrowplacebo injectionlongrightarrowmixed diet). Blood glucose was analyzed at d1, d8 and d12 after streptozotocin injection. At the end of the experimental period, fecal bifidobacteria, plasma insulin, total lipid, triglyceride, cholesterol, and leptin concentrations was analyzed, After STZ injection, blood glucose level was significantly elevated in experimental group compared to a control group. Elevated blood glucose level declined faster in OO group compared to the other experimental groups. Meanwhile, insulin concentration decreased in all experimental groups compared to a control group. The number of bifidobacteria was significantly increased in oligosaccharide diet groups after STZ injection (MO and OO) than a mixed diet group(MM). Plasma cholesterol concentration significantly decreased in oligosaccharide diet groups(MO and OO) compared to mixed diet groups (MM and OM) after SZ injection. Plasma triglyceride and liver cholesterol concentrations significantly decreased in MO group compared to other experimental groups. Meanwhile, plasma leptin concentration was significantly lower in oligosaccharide diet groups after STZ injection(MO and OO) compared to a control group. The results in this study suggest that the dietary soyoligosaccharides has strong on reduction of reduction of blood glucose and lipid concentrations in streptozotoicin-induced diabetic rats. Thus, the use of soyoligosaccharides at a diet for IDDM patients may help to improve diabetes mellitus symptoms.(Korean J Nutrition 34(1) : 3-13, 2001)

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A Study on the Adjusting Fine Method of Tap-off for CATV Transmitting Circuits Using Coupled-Line Theory (결합선로이론을 이용한 CATV 전송회로용 Tap off의 미조정방법에 관한 연구)

  • 김동일;민경식;정세모
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.6
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    • pp.26-33
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    • 1994
  • Much time and labor has been conventionally paid for fine adjustment of circuit elements by experience to improve the characteristics of Tap-off for CATV systems. To solve the problem, in this paper, the relations between the even- and odd-mode impedance. Z$_{oe}$ and Z$_{oo}$ of symmetrical 4-port coupled-line directional coupler and power dividing characteristics of Tap-off for CATV system have been derived. After the coupling, the reflectivity and the isolation are represented by Z$_{oe}$ and Z$_{oo}$ only, the fine adjustment of all S-parameters can be performed by controling the elements of Z$_{oe}$ and Z$_{oo}$ only. Furthermore, the validity of the new fine adjustment method proposed here has been confirmed by experiments.

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