• Journal of Information Technology Services
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• v.19 no.2
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• pp.109-124
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• 2020

Facing the 4^th Industrial Revolution era, researches on artificial intelligence have become active and attempts have been made to apply machine learning in various fields. In the field of finance, Robo Advisor service, which analyze the market, make investment decisions and allocate assets instead of people, are rapidly expanding. The stock price prediction using the machine learning that has been carried out to date is mainly based on the prediction of the market index such as KOSPI, and utilizes technical data that is fundamental index or price derivative index using financial statement. However, most researches have proceeded without any explicit verification of the prediction rate of the learning data. In this study, we conducted an experiment to determine the degree of market prediction ability of basic indicators, technical indicators, and system risk indicators (AR) used in stock price prediction. First, we set the core parameters for each financial indicator and define the objective function reflecting the return and volatility. Then, an experiment was performed to extract the sample from the distribution of each parameter by the Markov chain Monte Carlo (MCMC) method and to find the optimum value to maximize the objective function. Since Robo Advisor is a commodity that trades financial instruments such as stocks and funds, it can not be utilized only by forecasting the market index. The sample for this experiment is data of 17 years of 1,500 stocks that have been listed in Korea for more than 5 years after listing. As a result of the experiment, it was possible to establish a meaningful trading strategy that exceeds the market return. This study can be utilized as a basis for the development of Robo Advisor products in that it includes a large proportion of listed stocks in Korea, rather than an experiment on a single index, and verifies market predictability of various financial indicators.

• Health Policy and Management
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• v.20 no.3
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• pp.123-137
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• 2010

The main purpose of this article is for deriving functions related to the prediction of the closure of the hospitals, and finding out how the discriminant functions affect the closure of the hospitals. Empirical data were collected from 3 years financial statements of 41 private hospitals closed down from 2000 till 2006 and 62 private hospitals in business till now. As a result, the functions related to the prediction of the closure of the private hospital are 4 indices: Return on Assets, Operating Margin, Normal Profit Total Assets, Interest expenses to Total borrowings and bonds payable. From these discriminant functions predicting the closure, I found that the profitability indices - Return on Assets, Operating Margin, Normal Profit Total Assets - are the significant affecting factors. The discriminant functions predicting the closure of the group of the hospitals, 3 years before the closure were Normal Profit to Gross Revenues, Total borrowings and bonds payable to total assets, Total Assets Turnover, Total borrowings and bonds payable to Revenues, Interest expenses to Total borrowings and bonds payable and among them Normal Profit to Gross Revenues, Total borrowings and bonds payable to total assets, Total Assets Turnover, Total borrowings and bonds payable to Revenues are the significant affecting factors. However 2 years before the closure, the discriminant functions predicting the closure of the hospital were Interest expenses to Total borrowings and bonds payable and it was the significant affecting factor. And, one year before the closure, the discriminant functions predicting the closure were Total Assets Turnover, Fixed Assets Turnover, Growth Rate of Total Assets, Growth Rate of Revenues, Interest expenses to Revenues, Interest expenses to Total borrowings and bonds payable. Among them, Total Assets Turnover, Growth Rate of Revenues, Interest expenses to Revenues were the significant affecting factors.

• The Journal of Korean Physical Therapy
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• v.33 no.3
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• pp.168-177
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• 2021

Purpose: This study applies the ICF to identify the patient's body function, structure, and participation, evaluates the patient's environmental factors and individual factors, and is a high level of movement to return to the society of patients with multiple ligament injury of the knee joint. Methods: Progressive strength training and ROM exercise were performed 30 minutes a day, 5 times a week for 6 weeks. The evaluation was performed by examining the ROM, length, MMT, instability, dynamic balance, pain and depression. Results: The ROM of the knee joint was improved from 110° to 135° after intervention, and the knee flexion length decreased from 69 cm to 45 cm. Knee flexor is Good after intervention from Poor-, and knee extensor is Good+ after intervention from Poor, and the plantar flexor of the ankle joint improved from Poor- before intervention to Good after intervention and dorsi-flexor of the ankle joint improve to Good from Poor. Pain index was moderate before and after the intervention, with a score of 3, 2 after the intervention, and when maintaining the sitting cross-legged, the before intervention score was 7 to 4 after the intervention. Conclusion: The patient's posture of sitting cross-legged was maintained from 30 seconds before intervention to 14 minutes after intervention. These results were able to set the hypothesis design, intervention method and goal that the multifaceted approach of environment and individual factors as well as body function and structure area, activity and participation area using ICF checklists, it is helped the patient to return to daily life.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.3
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• pp.27-38
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• 2012

The purpose of this study is to analysis the concept of location efficiency, a base for the qualitative evaluation of TOD, and to propose the method of urban design for the improvement of location efficiency. Because of the environmental crisis by urbanization, sprawl and global warming, the importance of the solution through TOD has been increasing. For the future development of TOD, it becomes important to evaluate TOD qualitatively. From the study, it is grasped that location efficiency contains the concepts of value recapture, QoL and choice, financial return, and efficient regional land use and patterns. And the method of urban design for location efficiency is proposed as the followings: Form Based Zoning as land use plan, TOD and TOC model as node function, and street systems, mixed-use development, characteristic housing with various types, and networking of neighborhood facilities as place function.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.220-228
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• 2020

Breast cancer incidence continues to increase, and survival rates are also increasing compared to the past. An increase in breast cancer survivors means an increase in the number of women who return to their life after treatment. These patients feared cancer recurrence, which makes it an important aspect to be studied among breast cancer survivors. Therefore, this study was aimed at analyzing the concept of breast cancer survivors' fear of recurrence. The procedure of concept analysis developed by Walker and Avant (2011) was used to clarify and describe the concept. Studies published from 2007 to 2017 were searched through domestic and foreign electronic databases. Finally, 15 studies were selected and included in analysis. Through concept analysis, the scope of use of the fear of recurrence among breast cancer survivors was confirmed, and concept analysis was performed to confirm the antecedent, consequences, attributes and empirical criteria. Based on the analysis, the attributes of the fear of recurrence among breast cancer survivors included 1) worry about health status, 2) ineffective coping, and 3) possibility of changes. The antecedents of the fear of recurrence among breast cancer survivors were 1) healthcare-related activity, 2) perception of cancer, and 3) perceived severity; the consequences were 1) increase in distress, 2) difficulty in role function, and 3) decrease in the quality of life. This study provides a clear definition of the fear of recurrence among breast cancer survivors, and the results can be applied to improve the understanding of breast cancer survivors who have finished treatment and to help them return to daily life.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.303-309
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• 2022

Software Defined Networking (SDN) is a novel approach that have accelerated the development of numerous technologies such as policy-based access control, network virtualization, and others. It allows to boost network architectural flexibility and expedite the return on investment. However, this increases the system's complexity, necessitating the expenditure of dollars to assure the system's security. Network Function Virtualization (NFV) opens up new possibilities for network engineers, but it also raises security concerns. A number of Internet service providers and network equipment manufacturers are grappling with the difficulty of developing and characterizing NFVs and related technologies. Through Moodle's efforts to maintain security, this paper presents a detailed review of security-related challenges in software-defined networks and network virtualization services.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.2039-2043
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• 2007

Like other major river basin systems in the West of the United States the Platte River Basin are faced with the challenges of allocating more water for plant and animal species. A part of the Central Platte River was designated as critical habitat for the whooping crane in 1978. The water allocation system in the Platte River Basin is dominated by the Prior Appropriation Doctrine, which allocates water according to the priorities based on the date of water use. The Platte River Basin segregated into five subregions for purpose of analysis. 24 years of historic records of monthly flow and all the demands were complied. The simulation of river basin modeling includes physical operation of the system including water allocation by water rights and interstate compact agreements, reservoir operations, and diversion with consumptive use and return flow. MODSIM, a generalized river basin network model, was used for estimating the timing and magnitude of impacts on river flows and diversions associated with water transfers from each region. A total of 20 alternatives were considered, covering transfers from each of the five regions of basin with several options. The result shows that the timing and availability of augmented water at the critical habitat is not only a function of use by junior appropriators, but also of river losses, and timing of return flows.

• 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.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.140-145
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• 2005

In this paper, an experimental investigation for return loss and a software-based prediction for interference level of single-packaged filtering antenna composed of dielectric waveguide filter and PCB(Printed Circuit Board) slot antenna in transceiver module have been carried out with several different feeding structures in millimeter-wave regime. The implementation and embedding method of the existing air-filled waveguide filters working at millimeter-wave frequency on general PCB substrate have been described. In a view of the implementation of each components, the dielectric waveguide embedded in PCB and LTCC(Low Temparature Co-fired Ceramic) substrates has employed the via fences as a replacement with side walls and common ground plane to prevent energy leakage. The characteristics of several prototypes of filtering antenna embedded in PCB substrate are considered by comparing the wideband and transmission characteristics as a function of bent angle of transmission line connecting two components. In addition, as an essential to the packaging of transceiver module working at millimeter-wave, miniaturization technology maintaining the performances of independent components and the important problems caused by integrating and connecting the different components in different layers are described in this paper.

• 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.