• 산업공학
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• 제14권2호
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• pp.111-119
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• 2001

A tandem AGV system is based on partitioning all the stations into non-overlapping single vehicle closed loops with additional stations provided as an interface between adjacent loops. For an efficient use of this configuration, it is required to solve the load routing problem(LRP), which is primarily based on the fact that a load may be handled by several vehicles and moved through several loops before it reaches its destination. In this paper, a heuristic based on genetic algorithm(GA) is first developed to solve LRP. The first model obtains the optimal route of each job and the optimal direction of each loop when the vehicle in each loop travels unidirectionally. The second GA model obtaines the optimal polling sequence of the empty vehicle in each loop, when the vehicle can move bidirectionally.

• Journal of Advanced Marine Engineering and Technology
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• 제29권2호
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• pp.236-242
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• 2005

Dynamic Positioning(DP) system maintains ship's position (fixed location or predetermined track) exclusively by means of CPPs and thrusters. To generate the control input adequate to various situation an integrated controller for CPPs and thrusters is required. The integrated controller is composed of a thrust calculation algorithm and a thrust allocation algorithm. The thrust calculation algorithm generates thrusts in the surge direction and the sway direction from the desired forward and lateral speed and generates a moment about the yaw axis from desired heading angle. The thrust allocation algorithm allocates the generated thrusts and moment to each CPP and thruster. Computer simulations are executed to confirm the effectiveness of the suggested controller.

• Journal of Forest and Environmental Science
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• 제39권3호
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• pp.150-154
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• 2023

Heloniopsis orientalis (Liliaceae) is an important horticultural crop native to Korea. Under natural conditions, germination is poor and plant growth is delayed. Therefore, we have developed a vegetative propagation method to produce plants with vigorous growth characteristics via tissue culture. The regenerated shoots were then initiated directly from leaf explants on an MS medium containing either 0.5 to 2.0 mg/L 2,4-D or 1.0 to 3.0 mg/L BA. Healthy plantlets with adventitious roots were formed on the medium supplemented with 1.0 mg/L BA (81%). BA triggered callus initiation without caulogenesis or rhizogenesis, and callus formation was better on the half-strength MS medium than on the full-strength medium. This in vitro propagation protocol will be useful for conservation, as well as for mass propagation.

• Journal of Veterinary Science
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• 제24권5호
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• pp.68.1-68.6
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• 2023

Leopard cat (Prionailurus bengalensis euptilurus) is a small wild cat assessed as an endangered wildlife in Korea. There have been very few reports of their diseases. Herein, we describe fibrinous pleuritis caused by Streptococcus canis infection with excessive pleural effusion, hydropericardium, mild ascites, and liver fibrosis in a leopard cat. S. canis is a commensal microflora in domestic cats and often affects the upper respiratory tract inducing chronic and severe respiratory diseases. However, there is no literature regarding the S. canis in leopard cats. Therefore, we first report fibrinous pleuritis associated with an S. canis infection in a leopard cat.

• 품질경영학회지
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• 제36권3호
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• pp.76-86
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• 2008

This paper examines when a consumer in existent telecommunication 2G applies to new telecommunication service 3G from the viewpoint of an option pricing theory. To improve telecommunication quality of service, the consumer applies to 3G. The application means an exchange of 2G for 3G with extra costs such as searching and conversion costs. Since the option to exchange is a right that the consumer can exercise or not, application to 3G is deemed an exercise of the option to exchange at most suitable value of the option. The timing to exercise the option depends on the extra costs and the additional communication benefit from new telecommunication quality of service. These affect an optimal timing to apply to 3G. The optimal applying or switching timing to 3G is when an economic value of the option to exchange is equal to an economic value of the extra costs plus the additional telecommunication quality from new telecommunication service. The option analysis used in this paper is applicable to various industries.

• Clinical and Experimental Pediatrics
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• 제59권sup1호
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• pp.112-115
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• 2016

Noonan syndrome is an autosomal dominant, multisystem disorder. Autoimmune thyroiditis with hypothyroidism is an infrequent feature in patients with Noonan syndrome. A 16-year-old boy was admitted because of chest discomfort and dyspnea; an echocardiogram revealed pericardial effusion. Additional investigations led to a diagnosis of severe hypothyroidism due to Hashimoto thyroiditis. The patient was treated with L-thyroxine at 0.15 mg daily. However, during admission, he developed symptoms of cardiac tamponade. Closed pericardiostomy was performed, after which the patient's chest discomfort improved, and his vital signs stabilized. Herein, we report a case of an adolescent with Noonan syndrome, who was diagnosed with Hashimoto thyroiditis with an unusual presentation of cardiac tamponade.

• 콘크리트학회논문집
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• 제19권3호
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• pp.385-389
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• 2007

In this study, it was investigated the resistance of OPC, 60% GGBS, 20% PFA and 10% SF mortar specimens against sulfuric acid corrosion. As an index for degree of acid corrosion, the corrosion depth was evaluated. Then, it was found that an increase in the duration of immersion and a decrease in the pH, as expected, resulted in a more severe corrosion irrespective of binders; 60% GGBS mortar specimen was the most resistant to sulfuric acid corrosion. From the laboratory testing of sulfuric acid corrosion, an empirical prediction model was suggested as a power function of time and the pH of sulfuric acid, and was applied to an assessment of concrete structures exposed to an acidic environment. It was found that the empirical model gave a more precise prediction of sulfuric acid deterioration of concrete rather than a conventional model, mostly used for predicting carbonation of concrete.

• 한국군사과학기술학회지
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• 제15권2호
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• pp.169-176
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• 2012

GPS(Global Positioning System) is widely used for the position estimation of an aerial vehicle. However, GPS may not be available due to hostile jamming or strategic reasons. A vision-based position estimation method can be effective if GPS does not work properly. In mountainous areas without any man-made landmark, a horizon is a good feature for estimating the position of an aerial vehicle. In this paper, we present a new method to estimate the position of the aerial vehicle equipped with a forward-looking infrared camera. It is assumed that INS(Inertial Navigation System) provides the attitudes of an aerial vehicle and a camera. The horizon extracted from an infrared image is compared with horizon models generated from DEM(Digital Elevation Map). Because of a narrow field of view of the camera, two images with a different camera view are utilized to estimate a position. The algorithm is tested using real infrared images acquired on the ground. The experimental results show that the method can be used for estimating the position of an aerial vehicle.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.813-820
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• 2009

A rapid pneumatic transfer system (PTS) for an instrumental neutron activation analysis (INAA) is developed as an automatic irradiation facility involving the measurement of a short half-life nuclide and a delayed neutron counting system. Three new PTS designs with improved functions were constructed at the HANARO research reactor in 2006. The new system is composed of a manual system and an automatic system for both an INAA and a delayed neutron activation analysis (DNAA). The design and basic conception of a modified PTS are described, and the functions of system operation and control, radiation protection and emissions of radioactive gas are improved. In addition, a form of capsule transportation of these systems is tested. The experimental results pertaining to the irradiation characteristics with variation of the neutron flux and the temperature of the irradiation position with the irradiation time are presented, as is an analysis of the reference material for analytical quality control and uncertainty assessments.

• Biomolecules & Therapeutics
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• 제16권2호
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• pp.95-99
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• 2008

Apoptosis is essential for a variety of pathophysiological progress. Apoptosis induction by various agents changes cellular morphology, DNA content and lipid membrane composition. Recently, sphingosine 1-phosphate (S1P) is avidly released from not only platelets and erythrocytes but vascular endothelium. Here we established S1P releasing cells by deleting S1P lyase (F9-12 cells). We observed apoptosis induction by the treatment of fumonisin B1 (FB1) in F9-12 cells but not in F9 wild-type cells. We measured high amounts of accumulated S1P and dihydroS1P (DHS1P) in FB1-induced apoptotic F9-12 cells. We also showed DHS1P release in an early stage of the apoptosis induction by FB1 but not by phorbol 12-myristate 13-acetate (PMA)-induced apoptosis, suggesting differential apoptotic processes.