• Communications for Statistical Applications and Methods
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• 제4권2호
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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.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2005년도 추계학술대회 및 정기총회
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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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• 제43권5호
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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.

• 해양환경안전학회지
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• 제27권1호
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• pp.38-46
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• 2021

4차 산업혁명 시대를 맞이하면서 첨단기술이 산업 전반에 사용됨에 따라 자율운항선박기술에 대한 관심이 고조되고 있다. 이에 본 연구에서는 자율운항선박에 대한 기초 연구로써 모형 선박을 제작하고 드론에 사용되는 아두파일럿(Ardupilot)을 적용시켜 자율운항 제어 시스템을 구축하였다. 구축된 모형선을 활용하여 다양한 항해계획을 실행함으로써 자율운항 선박의 운항 자동제어 가능성을 확인하였다. 침로안정성 실험에서는 모형선이 정해진 침로를 똑바로 따라가지 못하고 지그재그(S자 형태)로 항행하면서 침로에서 최대 5.4 m(4.5 L) 이탈하였으며, 매개변수를 수정하여 이탈거리를 최대 1.8 m(1.5 L)까지 감소시켰다. 선회성능 실험에서는 선회권의 직경이 최대 약 9.3 m(7.8 L)로 나타났는데 매개변수를 수정하여도 큰 변화를 확인할 수 없었다. 하지만 WP 도착 전 감속하도록 실험한 결과 선회권의 직경이 최대 약 3.2 m(2.7 L)로 감소된 것을 확인할 수 있었다. 정지성능을 평가하기 위해 모든 실험의 마지막 정지 예정 위치와 실제 모형선이 정지한 위치를 상호 비교하였으며, 정지 예정 위치로부터 최소 0.4 m(0.3 L), 최대 6.2 m(5.2 L) 떨어진 지점에서 모형선이 정지하였음을 확인할 수 있었다. 추후 다양한 매개변수의 수정·보완을 통한 성능 향상이 이루어진다면 자동제어를 통한 자율운항선박의 자동접안을 위한 연구를 진행할 계획이다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제15권2호
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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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• 제17권3호
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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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• 제11권1_2호
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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.

• 대한한방소아과학회지
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• 제18권1호
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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).

• 한국항해학회지
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• 제15권4호
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• pp.27-39
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• 1991

출발, 정지, 후진, 가속, 감속 등을 포함하는 저속 항행시의 조종운동을 예측하기 위해서, 선체, 프로펠러, 타에 작용하는 유체력의 특징을 검토하여 이를 수식모델화 하였으며, 제안된 수식모델을 이용하여 유조선, 가스운반선 두 선박에 대해 저속시의 조종운동 시뮬레이션 계산을 수행하여 실험결과와 비교 검토하였다

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2012년도 제46차 하계학술발표논문집 20권2호
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• pp.433-434
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• 2012

본 연구에서는 쓰레기 매립장 내에서의 차량의 이동경로와 매립시점을 판단할 수 있는 방법을 제시한다. 현재의 영상과 배경영상의 차를 구하여 차량의 이동경로를 추적하고 이동경로의 형태로부터 정차 여부를 판단할 수 있으며, 정차시의 영상과 배출구의 개방영상과의 비교를 통해 폐기물의 매립시점을 검출할 수 있도록 한다.