• Title/Summary/Keyword: optimal return function

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OPTIMAL IMPULSE AND REGULAR CONTROL STRATEGIES FOR PROPORTIONAL REINSURANCE PROBLEM

  • RUI-CHENG YANG;KUN-HUI LIU;BING XIA
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.145-158
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    • 2005
  • We formulate a stochastic control problem on proportional reinsurance that includes impulse and regular control strategies. For the first time we combine impulse control with regular control, and derive the expected total discount pay-out (return function) from present to bankruptcy. By relying on both stochastic calculus and the classical theory of impulse and regular controls, we state a set of sufficient conditions for its solution in terms of optimal return function. Moreover, we also derive its explicit form and corresponding impulse and regular control strategies.

Estimating Paddy Rice Evapotranspiration of 10-Year Return Period Drought Using Frequency Analysis (빈도 분석법을 이용한 논벼의 한발 기준 10년 빈도 작물 증발산량 산정)

  • Yoo, Seung-Hwan;Choi, Jin-Yong;Jang, Min-Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.3
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    • pp.11-20
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    • 2007
  • Estimation of crop consumptive use is a key term of agricultural water resource systems design and operation. The 10-year return period drought has special aspects as a reference period in design process of irrigation systems in terms of agricultural water demand analysis so that crop evapotranspiration (ETc) about the return period also has to be analyzed to assist understanding of crop water requirement of paddy rice. In this study, The ETc of 10-year return period drought was computed using frequency analysis by 54 meteorological stations. To find an optimal probability distribution, 8 types of probability distribution function were tested by three the goodness of fit tests including ${\chi}^2$(Chi-Square), K-S (Kolmogorov-Smirnov) and PPCC (Probability Plot Correlation Coefficient). Optimal probability distribution function was selected the 2-parameter Log-Normal (LN2) distribution function among 8 distribution functions. Using the two selected distribution functions, the ETc of 10-year return period drought was estimated for 54 meteorological stations and compared with prior study results suggested by other researchers.

Stock Returns and Market Making with Inventory

  • Park, Seyoung;Jang, Bong-Gyu
    • Management Science and Financial Engineering
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    • v.18 no.2
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    • pp.1-4
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    • 2012
  • We study optimal trading strategy of a market maker with stock inventory. Following Avellaneda and Stoikov (2008), we assume the stock price follows a normal distribution. However, we take a constant expected rate of the stock return and assume that the stock volatility is an inverse function of the stock price level. We show that the optimal bid-ask spread of the market maker is wider for a higher expected rate of stock returns.

Service Experience Design Using CPTED: Location-Based Safe Return Home Assistance Application (셉테드(CPTED)를 이용한 서비스 경험디자인: 위치기반 안전 귀가 보조 어플리케이션 개발)

  • Chung, HaeKyung;Ko, JangHyok
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.48-53
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    • 2021
  • The purpose of this study is to establish a crime prevention system through the Crime Prevention Through Environmental Design (CPTED). The research method went through the double diamond process and discovered the user's needs through the persona analysis. The most representative features are the functions that informs users of the safe and optimal route, checks the presence of streetlights or cctvs in real time to update them, and allows people with similar routs to return home together. It is a function to help safe return home with the help of an autonomous method, and a self-defense function to protect themselves. Therefore, the application presented in this study was intended to be of great help when actually returning home by adding these new functions. In particular, we help users to return home most safely by recommending the best safe route. Through the persona analysis, research method which we had chosen, the needs of users were discovered and implemented in a design that reflected those needs and requirements.

A Clinical Study for Return to Work after Heart Valve Replacement - A Case Report - (심장판막 치환술후 직업복귀에 대한 임상적 고찰)

  • 김현경
    • Journal of Chest Surgery
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    • v.24 no.10
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    • pp.967-972
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    • 1991
  • Between Feb. 1982 and July 1990, 173 patients [male: 89, female: 84] Who underwent heart valve replacement for acquired valvular heart disease on the Department of Thoracic and Cardiovascular Surgery, School of Medicine, Pusan National University, were reviewed for return to work after heart valve replacement. The replaced valve were mitral [128, 74.0%], aortic[10, 5.8%], mitral & aortic[35, 20.2%]. Two tricuspid valve replacement were excluded. Several important factors influencing the return to work were age, the employment status before surgery, the number of replaced valve, the pre - op NYHA functional class and cardiac function [ejection fraction]. These factors were closely related to the optimal time of heart valve replacement. It can be concluded that the rate of return to work and the quality of life would be improved if valve replacement were performed at an earlier stage of valvular heart disease.

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A Study on Path Planning Algorithm of a Mobile Robot for Obstacle Avoidance using Optimal Design Method

  • Tran, Anh-Kim;Suh, Jin-Ho;Kim, Kwang-Ju;Kim, Sang-Bong
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.168-173
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    • 2003
  • In this paper, we will present a deeper look on optimal design methods that are related to path-planning for a mobile robot. To control the motion of a mobile robot in a clustered environment, it's necessary to know a suitable trajectory assuming certain start and goal point. Up to now, there are many literatures that concern optimal path planning for an obstacle avoided mobile robot. Among those literatures, we have chosen 2 novel methods for our further analysis. The first approach [4] is based on HJB(Hamilton-Jacobi-Bellman) equation whose solution is the return-function that helps to generate a shortest path to the goal. The later [5] is called polynomial-path-planning approach, in this method, a shortest polynomial-shape path would become a solution if it was a collision-free path. The camera network plays the role as sensors to generate updated map which locates the static and dynamic objects in the space. Therefore, the exhibition of both path planning and dynamic obstacle avoidance by the updated map would be accomplished simultaneously. As we mentioned before, our research will include the motion control of a true mobile robot on those optimal planned paths which were generated by above algorithms. Base on the kinematic and dynamic simulation results, we can realize the affection of moving speed to the stable of motion on each generated path. Also, we can verify the time-optimal trajectory through velocity tuning. To simplify for our analysis, we assumed the obstacles are cylindrical circular objects with the same size.

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Optimal Home Positioning Algorithm for a 6-DOF Eclipse-II Motion Simulator (6-자유도 Eclipse-II 모션 시뮬레이터의 최적 원점 복귀 알고리즘)

  • Shin, Hyun-Pyo;Kim, Jong-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.4
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    • pp.441-448
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    • 2012
  • This paper describes the optimal home positioning algorithm of Eclipse-II, a new conceptual parallel mechanism for motion simulator. Eclipse-II is capable of translation and 360 degrees continuous rotation in all directions. In unexpected situations such as emergency stop, riders have to be resituated as soon as possible through a shortest translational and rotational path because the return paths are not unique in view of inverse kinematic solution. Eclipse-II is man riding. Therefore, the home positioning is directly related to the safety of riders. To ensure a least elapsed time, ZYX Euler angle inverse kinematics is applied to find an optimal home orientation. In addition, the subsequent decrease of maximum acceleration and jerk values is achieved by combining the optimal return path function with cubic spline, which consequently reduces delivery force and vibration to riders.

Two-layer Investment Decision-making Using Knowledge about Investor′s Risk-preference: Model and Empirical Testing.

  • Won, Chaehwan;Kim, Chulsoo
    • Management Science and Financial Engineering
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    • v.10 no.1
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    • pp.25-41
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    • 2004
  • There have been many studies to build a model that can help investors construct optimal portfolio. Most of the previous models, however, are based upon the path-breaking Markowitz model (1959) which is a quantitative model. One of the most important problems with that kind of quantitative model is that, in reality, most of the investors use not only quantitative, but also qualitative information when they select their optimal portfolio. Since collecting both types of information from the markets are time consuming and expensive, making a set of target assets smaller, without suffering heavy loss in the rate of return, would attract investors. To extract only desired assets among all available assets, we need knowledge that identifies investors' preference for the risk of the assets. This study suggests two-layer decision-making rules capable of identifying an investor's risk preference and an architecture applying them to a quantitative portfolio model based on risk and expected return. Our knowledge-based portfolio system is to build an investor's preference-oriented portfolio. The empirical tests using the data from Korean capital markets show the results that our model contributes significantly to the construction of a better portfolio in the perspective of an investor's benefit/cost ratio than that produced by the existing portfolio models.

OPTIMAL LIQUIDATION OF A LARGE BLOCK OF STOCK WITH REGIME SWITCHING

  • Shin, Dong-Hoon
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.4
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    • pp.737-757
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    • 2011
  • This work is concerned with an optimal selling rule for a large position of stock in a market. Selling a large block of stock in a short period typically depresses the market, which would result in a poor filling price. In addition, the large selling intensity makes the regime more likely to be poor state in the market. In this paper, regime switching and depressing terms associated with selling intensity are considered on a set of geometric Brownian models to capture movements of underlying asset. We also consider the liquidation strategy to sell much smaller number of shares in a long period. The goal is to maximize the overall return under state constraints. The corresponding value function with the selling strategy is shown to be a unique viscosity solution to the associated HJB equations. Optimal liquidation rules are characterized by a finite difference method. A numerical example is given to illustrate the result.

Globally Optimal Recommender Group Formation and Maintenance Algorithm using the Fitness Function (적합도 함수를 이용한 최적의 추천자 그룹 생성 및 유지 알고리즘)

  • Kim, Yong-Ku;Lee, Min-Ho;Park, Soo-Hong;Hwang, Cheol-Ju
    • Journal of KIISE:Information Networking
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    • v.36 no.1
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    • pp.50-56
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    • 2009
  • This paper proposes a new algorithm of clustering similar nodes defined as nodes having similar characteristic values in pure P2P environment. To compare similarity between nodes, we introduce a fitness function whose return value depends only on the two nodes' characteristic values. The higher the return value is, the more similar the two nodes are. We propose a GORGFM algorithm newly in conjunction with the fitness function to recommend and exchange nodes' characteristic values for an interest group formation and maintenance. With the GORGFM algorithm, the interest groups are formed dynamically based on the similarity of users, and all nodes will highly satisfy with the information recommended and received from nodes of the interest group. To evaluate of performance of the GORGFM algorithm, we simulated a matching rate by the total number of nodes of network and the number of iterations of the algorithm to find similar nodes accurately. The result shows that the matching rate is highly accurate. The GORGFM algorithm proposed in this paper is highly flexible to be applied for any searching system on the web.