• Communications for Statistical Applications and Methods
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• v.4 no.2
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• pp.367-376
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• 1997

Consider the accelerated sequential procedure of Hall(1983). Second order asymptotic expression of well behaved functions of the stopping variable. The results is demonstrated by working out several point and interval estimation problems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.213-216
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• 2005

In this research, we explore how to manage the transition of technology generations considering incremental innovation of the existing technology generation. Firms can slow down decaying of the existing technology by continuous incremental improvements rather than introducing a new generation technology at the first time if the former strategy is better. We characterize optimal technology transition problem by setting up an optimal control model. The model which is originally designed and solved by Thompson(1968) as a ‘Machine maintenance problem’ has been cited to build the main body of our model. With this analytical model, we derive optimal ‘incremental innovation’ strategy which is considering transition to the next technology. Our analysis indicates that there exists an unique ‘stopping incremental innovation timing’. Before the point of time, the decision maker should make his effort at a maximum level to enhance the current technology. However from the stopping timing to the final time horizon where the new technology is introduced, it is found that not to invest to the current technology any more is optimal.

• ETRI Journal
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• v.43 no.5
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• pp.775-786
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• 2021

To translate in real time, a simultaneous translation system should determine when to stop reading source tokens and generate target tokens corresponding to a partial source sentence read up to that point. However, conventional attention-based neural machine translation (NMT) models cannot produce translations with adequate latency in online scenarios because they wait until a source sentence is completed to compute alignment between the source and target tokens. To address this issue, we propose a reinforced learning (RL)-based attention mechanism, the reinforced attention mechanism, which allows a neural translation model to jointly train the stopping criterion and a partial translation model. The proposed attention mechanism comprises two modules, one to ensure translation quality and the other to address latency. Different from previous RL-based simultaneous translation systems, which learn the stopping criterion from a fixed NMT model, the modules can be trained jointly with a novel reward function. In our experiments, the proposed model has better translation quality and comparable latency compared to previous models.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.38-46
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• 2021

In the era of the 4th Industrial Revolution, the interest in autonomous ship technology is increasing as high-tech technologies are being increasingly utilized throughout the industry. Therefore, we conducted a basic study on autonomous ships. In particular, a passenger ship model was produced and an autonomous navigation system was established by applying the ardupilot used for drones. The possibility of automatic control of the autonomous ship operations was confirmed by executing various voyage plans using the built model ship. In the performance test for maintaining the course the model ship could not follow the designated course straight and sailed up to 5.4 m away from the course while navigating in a zigzag (S-shape); however, after the parameters were modified, the deviation distance was reduced to a maximum of 1.8 m. In the turning performance test, the maximum diameter of the turning sphere was found to be approximately 9.3 m, but no significant change could be confirmed even after the parameters were modified. However, the results of our tests on slowing down the ship before arriving at the WP confirmed that the diameter of the turning sphere was reduced to a maximum of approximately 3.2 m. In order to evaluate the stopping performance, the last scheduled stopping position of all experiments was compared with the actual stopping position of the model ship and it was confirmed that the model ship stopped at a point at least 0.4 m and a maximum of 6.2 m away from the stopping position. In the future, improvement of course stability, turning performance, and stopping performance is required through modification and supplementation of various parameters. Moreover, a study on automatic berthing of the model ship through automatic control is planned.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.2
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• pp.151-160
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• 2011

Typically, it is hard to find a closed form solution of option pricing formula under an asset governed by a change point process. In this paper we derive a closed-form solution of the valuation function for an American perpetual put option under an asset having a change point. Structural changes are formulated through a change-point process with a Markov chain. The modified smooth-fit technique is used to obtain the closed-form valuation function. We also guarantee the optimality of the solution via the proof of a corresponding verification theorem. Numerical examples are included to illustrate the results.

• Natural Product Sciences
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• v.17 no.3
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• pp.165-174
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• 2011

Naturally occurring small molecules from plants, microorganisms, and animals allow the design of drugs that can be beneficial in virtually all kinds of human diseases. Liver diseases with diverse etiologies such as viral infection, chemical intoxication, and metabolic fat accumulation are one of the leading causes of human mortality. Unfortunately, however, there are few effective drugs available capable of stopping or reversing the progress of liver disease. Here, we discuss the current advances in developing hepatoprotective natural products for several arrays of liver disease pathogenesis.

• Journal of applied mathematics & informatics
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• v.11 no.1_2
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• pp.201-213
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• 2003

In this paper we present a second order PVT (parallel variable transformation) algorithm converging to second order stationary points for minimizing smooth functions, based on the first order PVT algorithm due to Fukushima (1998). The corresponding stopping criterion, descent condition and descent step for the second order PVT algorithm are given.

• The Journal of Pediatrics of Korean Medicine
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• v.18 no.1
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• pp.105-129
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• 2004

Methods: It was studied on the 47 kinds of oriental medical literature for fecal blood. Results: Fecal blood means bleeding with faces from anus and indicates all the three cases such as blooding before and after evacuation, evacuation of feces mixed with blood, and simple melena. The main causes are fire(火) and deficiency of spleen qi (脾氣虛). According to the color of fecal blood and the region of the bleeding, first, if the blood color is dark-red and blood discharges after emptying the bowels, it is called deposited poison into Jang(臟毒) or distant bleeding(遠血), and if the color of blood is clear and bowel emptying occurs after bleeding, it is bloody stool due to intestinal wind(腸風) or nearby bleeding(近血). For treating methods(治法). removing heat from the blood and stopping bleeding(淸熱凉血止血), removing dampness and stopping bleeding(淸熱除濕止血), invigorating Ki for promoting Hul-controJ(益氣攝血), warming the spleen and stomach to dispel cold and stopping bleeding(溫中散寒止血) etc are applied. As for the treating prescriptionl(治法), a Hwangtotang(黃土湯). Jeoksodudanggwitang(赤小豆當歸散). Gwihwasan(槐花散). Wipungtang(胃風湯). Hwangnyeonhwan modifying(黃連丸加減). Samultang modifying(四物湯加減). Paedoksan modifying(敗毒散加減) etc are used. As for acupuncture and moxibustion(鍼灸療法). if etiology(病因) is damp-heat(濕熱), acupuncture(刺鍼) at Janggang(長强); Charyo(BL 32); Sangeoheo(ST 37)(上巨虛); Seungsan(BL 57)(承山穴), and in case of deficiency of spleen Gi(脾氣虛), acupunture(刺鍼) with tonification(補法) at I Baek(EX-UE 2)(二白); Gwanwon(CC 4)(關元); Joksamni(ST 36)(足三里) Taebaek(SP 3)(太白); Hoeeum(CC 1)(會陰穴), or mxibuston(灸) at Baekoe(GC 2O)(百會); Myeongmun9GC (命門) or the point of opposite to umbilicus among spinal vertebrae(脊中對臍穴) are used. The external treatment(外治療法) was consisted of plastering umbilicus therapy(敷臍法) and enema therapy(灌腸法).

• Journal of the Korean Institute of Navigation
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• v.15 no.4
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• pp.27-39
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• 1991

One practical method has already been proposed for predicting the characteristics of ship manoeuvring motions at relatively high advance speed [19]. Howeverf, this method can hardly be applied to motions of ships in starting, stopping, backing and slow steaming conditions, even though such extensive motions are of vital importance from a safety point of view particularly in harbour areas. The method presented here aims at predicting the characteristics of ship manoeuvring at low advance speed, which covers starting, stopping, backing and slow steaming conditions. The force mathematical models at large angles of incidence to the hull as well as under the wide range of propeller operations are formulated. Simulations of various manoeuvres at low advance speed are carried out for two types of merchant ship, I.e. a LNGC and a VLCC. Comparisons between simulations and corresponding full-scale measurements [10], [15] or free-running model tests [6],[10] provide a first verification of the proposed mathematical models.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.433-434
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• 2012

In this paper, we developed the algorithm which tracking the vehicle and deciding the moment of dumping in landfills. We first trace the position of vehicle using the difference image between current image and background image and then we decide the stop point from the shape of vehicle route and detect the dumping point by comparing the dumping image with the image that vehicle is stopping.