• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.226-231
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• 2007

This paper describes a development of ultrasonic examination analysis software to analyze steam generator of nuclear power plant. The developed software includes classical analysis method such as A, B, C and D-scan images. This software provides the information of shape, depth, size and position of flaws. To do such, we obtain raw data from specimens and/or real pipeline of power plants and, modify the obtained ultrasonic 1-dimensional data according to prepared software design schedule. The developed analysis software is applied to specimens containing various flaws with known dimensions. The results of applications showed that the developed software provided accurate and enhanced images of flaws on various specimens.

• Polymer(Korea)
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• v.27 no.2
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• pp.129-134
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• 2003

It has been known that the intercalation of long alkyl chains in montmorillonites (MMT) increased the hydrophobicity as well as gallery spacing of UT, which has influenced on the exfoliation behavior of various polymers. A series of organophilic MMTs were synthesized from the water/isopropyl alcohol solution of MMT with ammonium salts of various alkyl amines. The properties of obtained MMTs such as thermal decomposition temperature, gallery spacing as well as hydrophobic property were investigated. The X-ray diffraction experiments on organophilic montmorillonite demonstrated that the increase of length of alkyl substituent resulted in increase in the spacing between silicate layers, which was ranged from 13.1 to 29.4 $\AA$. On the other hand, introduction of (di-, tri-) alkyl substituents in ammonium salts decreased water absorption of organophiplic montmorillonite to 2.7%.

• Tunnel and Underground Space
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• v.9 no.2
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• pp.102-113
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• 1999

Two-dimensional and three-dimensional DEM programs, UDEC and 3DEC, were used to investigate the mechanical stability of the conceptual design of deposition drift and deposition holes constructed in a crystalline rock mass. From the simulations, the influence of discontinuities, the number of deposition holes, and deposition hole interval on the stability of deposition drift and deposition holes could be determined. From the two-dimensional and three-dimensional analysis. it was concluded that three-dimensional analysis should be carried 7ut fur deriving reliable conclusions. Even though the deposition hole interval changed from 8 m to 3 m, which did not damage the mechanical stability of the deposition drift.

• The Journal of Korean Academic Society of Nursing Education
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• v.15 no.1
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• pp.53-61
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• 2009

Purpose: This study was conducted to evaluate the need for education for emergency care in nursing homes. Method: 312 people who were engaged in caring for the elderly at nursing homes in D-metropolitan c! ity answered the questionnaires about the experiences, the need, and the ideal methods of education for basic emergency care, from Jul. 1. 2007 to Jul. 30. 2007. Result: 69.9% were female. Only 7.1% were nurses and the rest did not have majors in the medical field. 83.0% had experienced education for emergency care, and 89.2%, 78.4% and 44.8% of them had been educated about cardiopulmonary resuscitation, airway obstruction care, and fracture/sprain/dislocation care respectively. Fifty-three who had not experienced education answered 'no opportunity' as a cause of non-education. The need for emergency care education was 4.53/5.00, and the desire to receive education was 2.81/3.00. Mainly workers wanted to be educated abo! ut airway obstruction (88.1%), and breathing assistance & cardiac massage (72.4%). Workers preferred to be educated 1-2 times per year for 2-3 subjects, through programs including both lecture and practice. Conclusion: It is essential to create an adequate program and apply it to the people engaged in caring for the elderly.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.34.3-35
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• 2016

Ram pressure stripping of early-type galaxies has been largely neglected until now because of their gas poor nature. MUSE IFU observation vividly reveal the presence of star-forming blobs and ionised gas tails, around an early-type galaxy in Abell 2670. The galaxy was identified as a post-merger galaxy with disturbed faint features, in MOSAIC 2 deep optical images. The imaging also revealed a series of star-forming blobs, situated in the direction facing away from the cluster centre. Thanks to the revolutionary wide field-of-view of the MUSE, combined with 8.2-m VLT (UT-4) at Cerro Paranal, we could simultaneously obtain IFU spectra of the blobs, as well as the galaxy. The MUSE spectra clearly confirms that the star-forming blobs are associated with the early-type galaxy. Moreover, MUSE reveals long ionised-gas tails, emanating from the galaxy. The quantity of gas indicates a gas rich progenitor has merged with the early-type galaxy. However the direction of the tails and blobs, and the blob morphology, appears to indicate that strong ram-pressure stripping may have stripped out gas brought in by the merger. We will present kinematic structure of the whole system (the galaxy, star-forming blobs, and gas tails), as well as the star formation history of the system, supporting a scenario where a recent galaxy merger is subjected to cluster environmental mechanisms.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.64-69
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• 2012

Dissimilar friction welds were produced using 15-mm diameter solid bars of chrome molybdenum steel (KS SCM440) and carbon steel (KS SM20C) to investigate their mechanical properties. The main friction welding parameters were selected to ensure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond area and HAZ, and macro-structure investigations. The specimens were tested as-welded and post-weld heat treated (PWHT). The tensile strength of the friction welded steel bars was increased to 100% of the SM20C base metal under the condition of a heating time of more than four seconds. Optimal welding conditions were n = 2,000 (rpm), HP = 60 (MPa), UP = 100 (MPa), HT = 5 (s),and UT = 5 (s), when the total upset length was 7.8 (mm). The hardness distribution peak of the friction welded joints could be eliminated using PWHT. The two different kinds of materials were strongly mixed to show a well-combined structure of macro-particles, with no molten material, particle growth, or defects.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.153-158
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• 2007

기존의 모바일 기기들은 일반화된 고정 인터페이스 상태의 제품으로, 사용자가 단순 학습을 통해 반복된 인터렉션과 구성만을 이용하는 수준이었으나 최근과 같이 기기가 지능적이고 다양화되면서 개인의 요구와 특성을 반영한 인터페이스 방법들을 요구하기 시작하였다. 이에 따라 일반적 성향에 맞추어진 Universal UI와 개인의 특성에 맞춰진 Customizing UI의 양립적 이슈는 지속적으로 대치되어 왔다. 그러므로 이를 서로 적절한 수준에서 상호 보완하여 디자인하는 것은 그 형태나 속성을 떠나 최신 UI의 기본적인 필요충분조건이 되었다. Universal UI는 인식과 행동패턴을 달리하는 사람들의 공통분모를 찾아냄으로써 표준화의 Solution을 찾아낼 수 있었지만 Customizing에 대한 해답은 사용자 심리, 문화, 역사까지 고려해야 한다. 우리는 이 두 부분을 모두 만족하는 다방면의 멘탈모델 수립과 UT검증을 통해 모바일 기기에서 최적의 인터페이스 개발을 진행하게 되었다. 이러한 Customizing에 대한 연구는 기기 사용자의 지역과, 문화적 특성에 따라 최적화된 인터페이스를 제공할 수 있기에 기기 제조사는 Future work을 위해서라도 이러한 부분에의 충분한 연구 의의가 있다고 할 수 있다. 우리는 본 논문에서와 같은 Personalization과, 선호 기능을 좀 더 쉽게 적응하고 사용할 수 있도록 하는 Customization 을 통해 사용자의 성향을 적극 반영할 수 있는 모바일 인터페이스 제품 개발로 한 단계 발전시켰다고 본다.

• Journal of Communications and Networks
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• v.15 no.5
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• pp.457-463
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• 2013

In recent days, cooperative diversity and communication security become important research issues for wireless communications. In this paper, to achieve low probability of interception (LPI) and high throughput in the cooperative single-carrier frequency division multiple access (SC-FDMA) system, a new physical layer transmission scheme is proposed, where a new encryption algorithm is applied and adaptive modulation is further considered based on channel state information (CSI). By doing so, neither relay node nor eavesdropper can intercept the information signals transmitted from user terminal (UT). Simulation results show above new physical layer transmission scheme brings in high transmission safety and secrecy rate. Furthermore, by applying adaptive modulation and coding (AMC) technique according to CSI, transmission throughput can be increased significantly. Additionally, low peak-to-average power ratio (PAPR) characteristic can still be remained due to the uniform distribution of random coefficients used for encryption algorithm.

• ETRI Journal
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• v.21 no.4
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• pp.23-28
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• 1999

In this paper, we analyze the performance benefits of broadband ATM networks when the call control and management flows are separated from user data flows. The virtual path tunneling concept for control and management flows are applied to the same physical ATM networks. The behaviors of channel throughput and transfer delay are analyzed. It results that the proposed virtual short-cut paths can maintain the network being stable with acceptable bandwidth. They are very useful to provide the stable control and management capabilities for Internet and mobile applications in the broadband ATM networks. In our numerical results, the effective throughputs of the proposed virtual shout-ut channel are about three times than those of end-to-end user data channels with hop distances of 10, and about two times than those with hop distance of 5 when the link blocking probability increases to 0.1. It concludes that the effective channel bandwidth are greatly reduced down while physical links are not stable and user traffic flows are occasionally overflowed.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.60.2-61
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• 2017

A Convolutional Neural Network(CNN) is one of the well-known deep-learning methods in image processing and computer vision area. In this study, we apply CNN to two kinds of flare forecasting models: flare classification and occurrence. For this, we consider several pre-trained models (e.g., AlexNet, GoogLeNet, and ResNet) and customize them by changing several options such as the number of layers, activation function, and optimizer. Our inputs are the same number of SOHO)/MDI images for each flare class (None, C, M and X) at 00:00 UT from Jan 1996 to Dec 2010 (total 1600 images). Outputs are the results of daily flare forecasting for flare class and occurrence. We build, train, and test the models on TensorFlow, which is well-known machine learning software library developed by Google. Our major results from this study are as follows. First, most of the models have accuracies more than 0.7. Second, ResNet developed by Microsoft has the best accuracies : 0.77 for flare classification and 0.83 for flare occurrence. Third, the accuracies of these models vary greatly with changing parameters. We discuss several possibilities to improve the models.