• Computational Structural Engineering
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• v.5 no.4
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• pp.133-142
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• 1992

An analytical model was developed for predicting the pullout behavior of straight beam longitudinal bars anchored at exterior beam-column connections. The model incorporates a local bond constitutive simulation capable of considering the effects of anchored bar diameter, yield strength and the spacing, concrete compressive strength, and column pressure on the bond characteristics of deformed bars in confined conditions of exterior joints. The analytical techniques adopted in this study were shown to satisfactorily predict the results of pullout tests on straight bars embedded in confined concrete specimens. An evaluation of the ACI-ASCE Committee 352 development length requirements in exterior joint conditions was made using the developed analytical approach. The results of this analytical evaluation are indicative of the conservatism of the current development length requirements in the confined conditions of exterior joints.

• Journal of Drive and Control
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• v.14 no.2
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• pp.9-15
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• 2017

The steering systems of all-terrain cranes have been developed with various control strategies for the stability and drivability. To optimally control the input steering angle, an accurate mathematical model that represents the actual crane dynamics is required. The derivation of an accurate mathematical model to optimally control the steering angle, however, is difficult since the steering-control strategy generally varies with the magnitude of the crane's longitudinal velocity, and the postures of the crane's working parts vary while it is being driven. To address this problem, this paper proposes an automatic steering-control algorithm that is based on the MPC (model predictive control) with a disturbance observer for all-terrain cranes. The designed disturbance observer of this study was used to estimate the error between the base steering model and the actual crane. A model predictive controller was used for the computation of the optimal steering angle, along with the use of the base steering model with an estimated uncertainty. Performance evaluations of the designed control algorithms were conducted based on a curved-path scenario in the Matlab/Simulink environment. The performance-evaluation results show a sound reference-path-tracking performance despite the large uncertainties.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.906-912
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• 2014

The study of fish robot is a main subject that are related with the propulsive force comparison using a varying amplitude and frequency for body and tail motion trajectory, and the quick turn using a proper trajectory function. In this study, when a fish robot thrusts forward, feedback control is difficult to apply for a fish robot, because body and tail joints as a sine wave are rolled. Therefore, we detect the virtual position based on the path of the fish robot, define the angle errors using the detected position and the look-ahead point on the given path, and design a controller to track given path. We have found that the proposed method is useful through the computer simulations.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.645-649
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• 2003

The variety conditions and working situations during decontamination and decommissioning practice may cause the production of metallic wastes, which can differ in character or in quantity from the waste anticipated during D&D planning. The management of such kind of wastes involves the need to evaluate existing waste management system in order to determine how metallic wastes should be well handled and treated. In this study, the investigation of existing management practices which can be also applied to the metallic waste management, was carried. Simultaneously, assistance in selection of appropriate technologies and processes is investigated which can be used when anticipated situations occur during decontamination and decommissioning practice.

• Journal of Energy Engineering
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• v.13 no.3
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• pp.205-213
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• 2004

Usefulness of an optical fiber was demonstrated by detecting the generation of self-excited combustion oscillations. OH chemiluminescence intensity detected by the optical fiber showed mostly excellent agreement with those obtained by high speed CCD camera measurements when combustion oscillations were strong. Symptoms of self-excited combustion oscillation were also studied in order to predict the onset of combustion oscillation before it proceeded to a catastrophic failure. For the purpose, we have found and proposed unique measures to tell the onset of self-excited combustion oscillations based on the careful statistics of fluctuating properties in flames, such as pressure or omission of OH radicals.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.55-60
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• 2008

Background: Circulating levels of brain natriuretic peptide (BNP) provide prognostic information for patients with heart failure. The aim of our study was to investigate whether preoperative and postoperative BNP levels could predict postoperative complications and outcomes in patients after coronary artery bypass graft (CABG). Material and Method: Data was collected prospectively on 30 patients (M/F=19/11, age $60.0{\pm}9.6$ years) undergoing conventional CABG during a 1-year period beginning on January 1, 2005. Patients underwent off-pump CABG, and combined surgery was excluded. The BNP assay was performed preoperatively, immediate postoperatively at the intensive care unit (ICU), and 1, 3, 5, and 7days postoperatively. Result: Preoperative BNP levels significantly correlated with preoperative echocardiographic ejection fraction and an ICU stay of 5 days or more (r=-0.4, p=0.028; r=0.39, p=0.031, respectively). A preoperative BNP cut-off value above 263 pg/mL demonstrated high specificity (90.5%) for predicting postoperative complications using the receiver operating characteristics curves. Preoperative and postoperative (7 days) BNP levels were different depending on the abscence (mean BNP=$99{\pm}23\;pg/mL$ vs. $296{\pm}74\;pg/mL$, p<0.05) and presence (mean BNP=$212{\pm}29\;pg/mL$ vs. $408{\pm}23\;pg/mL$, p<0.01). Conclusion: Preoperative BNP levels >263 pg/mL predict postoperative complications in patients receiving CABG.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.549-555
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• 1999

Background: Patients who are considered for major pulmonary resection are generally evaluated by spirometry and clinical assessment to predict morbidity and mortality. Despite this, none has yet proved to be a convenient and reliable estimate of risk. Material and Method: A retrospective analysis was performed in 167 patients who were diagnosed for lung cancer, bronchiectasis, pulmonary tuberculosis, and other benign pulmonary disease, and who underwent major lung resections. The relationship of 25 preoperative or postoperative variables to 19 postoperative events were classified into categories as operative mortality, pulmonary or cardiovascular morbidity, and other morbidity was assessed. Logistic regression analysis and $\chi$2 analysis were used to identify the relationship of the operative risk factors to the grouped postoperative complications. Result: The best single predictor of complications was the percent predicted postoperative diffusing capacity (pulmonary morbidity, p<0.009; cardiovascular morbidity, p<0.003: overall morbidity, p<0.004). Conclusion: The diffusing capacity of the lung for carbon monoxide was an important predictor of postoperative complications than the spirometry, and it usually should be a part of the evaluation of patients being considered for pulmonary resection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5741-5747
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• 2011

The purpose of this study was to find correlation between the Berg Balance Scale which is most commonly used and the equilibrium scores from Smart Balance Master System which is used for the test of the balance ability for the patients with chronic hemiparetic stroke to predict their falling risk though examining the postural control. Twenty-two subjects who had first stroke participated in this study. Participants were measured the Berg Balance Scale and the Smart Balance Master System. The study found that there was a significant correlation between the Berg Balance Scale and the equilibrium scores from Smart Balance Master System. And there was no significant correlation at all "eye-closed and sway of surfaces" in the 6 conditions of Smart Balance Master System and there was a significant correlation with over median in the other 5 conditions. The study was uncovered that there was no meaningful correlation between the Berg Balance Scale and "eye-closed and sway of surfaces" because chronic hemiparetic stroke patients heavily relied on their vision to maintain their balance ability and the Berg Balance Scale did not properly exam it. Thus to predict their falling risk in clinical practice for the patients with chronic hemiparetic stroke, it would be more efficient ways for us to consider all the effects of sensory organs with more than one clinical evaluation method.

• Digital Contents
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• no.2 s.117
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• pp.88-97
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• 2003

새로운 기술의 도입은 저작권 제도를 변화시키고 있다. 인쇄술의 발전에 따라 저작권의 보호에 대한 법제화가 이루어 졌고, 방송기술의 도입에 따라 방송권, 영화기술의 발전에 따라 영화에 대한 권리, 사진기술의 발전에 따른 사진에 대한 권리, 인터넷 등 정보통신 기술의 발전에 따라 전송권이 새로운 저작권자의 저작재산권의 한 유형으로 편입되고 있다. 이렇듯 저작권법은 기술의 발전에 따라 새로운 유형의 권리를 정책적 견지에서 수용하고 있으며, 앞으로도 예견되지 못한 기술의 출현에 따라 법의 개정은 이루어질 개연성이 크다.

• The Science & Technology
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• v.33 no.5 s.372
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• pp.18-19
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• 2000

현대의 대표적인 정밀가공기술의 하나는 반도체 가공기술이다. IMB메모리 반도체를 만드는 최소의 선폭은 1985년에는 I마이크로미터(㎛)였으나 현재의 256MB의 메모리 반도체에는 0.2㎛의 미세선폭이 사용되고 있다. 21세기에는 나노테크놀로지 기술이 정밀가공기술의 최선단을 이룰 것으로 예견되고 있는데 현재 국내의 미세가공기술은 메모리 반도체의 제조기술에 관한 한 세계의 선두를 달리고 있으며 0.18마이크론 선폭의 가공기술을 개발하여 1GB의 메모리 반도체 개발에 활용하고 있다.