장애인 전동휠체어 교통안전에 관한 연구

권성철,권창희 조선대학교 기초과학연구원 2022 조선자연과학논문집 Vol.15 No.2

서울시 성동구 교육복지센터의 역할 및 발전방안에 관한 연구

권성철 한국디지털정책학회 2018 디지털융복합연구 Vol.16 No.3

株式評價理論에 관한 硏究

權成哲 啓明大學 産業經營硏究所 1977 經營經濟 Vol.8 No.1

In this paper, we assumes that the objective of the firm is to maximize its market value of shareholder wealth because this principle provides a rational guide for running a business a for allocating resources efficiently in an economy. Shareholder wealth is represented by market price of the company's common stock, which, in turn, is a reflection of the firm's investment, financing, and dividend decisions. How do the investment and financing decisions of management affect the market value of the firm? The answer is equivocal and, like other areas in business finance, abounds with controversy. For example, the general problem of security valuation has attracted the attention of three major schools of thought: fundamentalists, technicians, and random-walk proponents. The fundamentalist approach seems to be most theoretical and produced a number of models. The existence of many divergent valuation models is the result of the various beliefs espoused by security analysts. It also depends on different views with respect to the possible relationships among the variables deemed to be most relevant in the implicit valuation process of investors and the usefulness of different models in determining or predicting future share price movements. The objective of this paper is to overview these approaches and to provide a foundation for the specification of certain functional relationship which can be verified in Korean Securities Market. 2. Fundamental Approach The proponents of the fundamental approach to security valuation believe that stock prices are reflections of the intrinsic value of the firm. They also believe that stock-price levels and movements can be explained and predicted in terms of the expected value of the relevant variables. They suggest that the market value of the firm be determined by such factors as earning, investment opportunities, and discounted-cash-flow information. Therefore, the basic problem to be solved in the fundamental school is the determination of what investors really capitalize when they make their decisions in the market. Fundamentalists are usually classified into four different models as follows: 1) Dividend valuation models. 2) Earnings valuation models. 3) Discounted-cash-flow models. 4) Investment-opportunities models. All above four valuation approaches are formally equivalent. We shall not prove this contention here, but we refer to the excellent paper by Miller and Modigliani("Dividend policy, growth and the Valuation Shares," Journal of Business, Oct., 1961) which shows that all these models derive from the same fundamental valuation equation. 3. Technical Approach The best-known representative of the technical approach is the chartists. Chartists believe that future stock prices can be predicted from their past price movements. They base this belief on the proposition that there are certain identifiable, recurrent of price movements that can be used to predict the future movements and trends of speculative prices. Chartists typically maintain a graphic record of a particular security's daily or weekly price, tracing range, and value traded. They also maintain the charts on a current basis and continually analyze them for trends that might be developing. The method of forecasting is not definite and precise, but is rather a sort of "eyeballing" approach which is more of an art than a discipline. Thus it not a technique that enjoy the support and confidence of the academic society. 4. Random-Walk Hypothesis In contrast to the contentions of the technicians and the fundamentalists that their framework can be used to predict share prices, the random-walk proponents refute the usefulness of either public or privileged information in forecasting market values. Indeed, in a series of studies, they have presented evidences that the use of such things as past prices, public announcements of dividends, earnings, and so on, or even monopolistic access to information is nearly inconsequential. The theory of random walks is basically composed of two hypotheses. They are: (1) Successive price changes in various stock exchanges are independent of previous movements. (2) Security price changes conform to some probability distribution. Both the technical and random-walk schools basically ignore the investment and financing decisions of the firm and attempt to predict market values on the basis of market patterns. 5. Financial Decisions and Market Valuation The financing decisions of the firm change the composition of the sources of funds and shirt the balance between debt and equity. The argument of capital structure between traditional view and Modigliani-Miller propositions notwithstanding, nearly all valuation theorists agree that the introduction of debt does affect the value of the firm in the market. Once we admit the importance of debt financing to the market valuation of a corporation we must attempt to provide some integrated framework which functionally relates the capital-budgeting and financing decisions of the firm to the behavior of stockholders in the marketplace. In this paper, three recently developed frameworks are explained, as follows; (1) The taxonomic reconciliation of financing and valuation proposed by W.R. Sloane and A. Reisman, in which various methods of equity and debt financing are introduced into a generalized valuation model. (2) The functional integration of budgeting, financing, and valuation proposed by Eugene . Lerner and Willard T. Careleton. (3) A generalization of the market valuation process along the lines of state-preference theory recently attempted by S. C. Myers. 6. Valuation Models: Limitations and Future Directions What matters with security valuation model? It may be the empirical validity of the behavioral assumptions incorporated in these models. Some were empirically tested; some were not or perhaps, given the state of the art and technology, cannot be tested completely. There are several explanations for the poor empirical performance of testable valuation models. First, most of these models are restricted analytically be unacceptable behavioral assumptions and empirically by the employment of standard regression methodology. Second, the quality of input data does not guaranteed higher compatibility or consistency with structural form of the model. Third the typical equity valuation model is mechanistic in nature and does not allow imaginative behavior based on adaptive learning and changes in expectations. Finally, the problem of valuation within the context of uncertainty is very difficult and does not lend itself easily to precise specifications. These problems also map out future areas of fruitful research. In this view, Keenan suggests three major areas of interest, as follows: (1) Research into the formation of investor expectations. (2) Research into the problem of capital structure and its effects upon share-price valuation. (3) Research into the interactions of the firm and the public sector.

Numerical Feasibility Study for a Spaceborne Cooler Dual-function Energy Harvesting System

권성철,오현웅 한국항공우주학회 2017 International Journal of Aeronautical and Space Sc Vol.18 No.3

Spaceborne cryocoolers produce undesirable micro-vibration disturbances during their on-orbit operation, which are a primary source of image-quality degradation for high-resolution observation satellites. Therefore, to comply with the strict mission requirement of high-quality image acquisition, micro-vibration disturbances induced by cooler operation have always been subjected to an isolation objective. However, in this study, we focused on the applicability of energy harvesting technology to generate electrical energy from micro-vibration energy of the cooler and investigated the feasibility of utilizing harvested energy as a power source to operate low-power-consumption devices such as micro-electromechanical system (MEMS) devices. A tuned mass damper (TMD)-type electromagnetic energy harvester combined with a conventional passive vibration isolator was proposed to achieve this objective. The system performs the dual functions of electrical energy generation and micro-vibration isolation. The effectiveness of the strategy was evaluated through numerical simulations.

한국과 일본의 장기요양제도의 형성과 전개과정에 관한 비교 고찰

권성철 동아시아일본학회 2019 일본문화연구 Vol.0 No.69

The purpose of this study is to elucid the policy implication for finding the developmental alternatives of long - term care insurance system for the elderly in Korea through the comparative study on the formation and development process of the long - term care system with Japan which experienced aging before Korea. As a result of the analysis, it was concluded that developmental alternatives such as building an integrated care policy system, strengthening preventive function of long - term care system, and the reinforcement of education of the specialized personnel in long-term care accommodation. This study firstly discusses the current status and the formation process of the long - term care system of both countries. Second, the policy tasks and development plans of the long - term care policies of the two countries were compared and analyzed. Through this study, it is important to derive the implications of social welfare which is important for the development plan of long - term care insurance system in Korea.

우주용 냉각기 미소진동 절연을 위한 에너지 재생형 진동절연시스템

권성철,오현웅 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.4

위성용 적외선 센서를 극저온으로 유지하기 위해 Pulse Tube-type의 우주용 냉각기가 사용되며, 이는 궤도 운용 시 미소진동을 발생하여 고해상도 관측위성의 지향성능을 저하시키는 원인으로 작용한다. 따라서 고 해상도 영상을 획득하기 위해 일반적으로 냉각기로부터 발생하는 미소진동은 항상 차폐의 대상으로만 존재하였다. 본 연구에서는 이에 주목하여 동 흡진기 형태의 에너지 재생형 진동절연시스템을 고안하였으며, 이를 기존의 수동형 진동절연기에 결합함으로써 냉각기로부터의 미소진동 에너지를 전기에너지로 재생함과 동시에 진동절연 성능의 확보가 가능함을 수치해석을 통해 입증하였다. Pulse Tube-type Spaceborne cryocooler is widely used to cool down the infrared sensor of observation satellite. However, it generates a micro-vibration which is the one of the source to degrade the pointing performance during on-orbit operation. Therefore, a micro-vibration has always been subjected to an useless isolation objective. In this study, we have proposed the tuned mass damper type energy harvesting vibration isolation system combined with an existing passive micro-vibration isolator to generate electrical energy from the spaceborne cryocooler micro-vibration and to obtain the additional isolation performance. The feasibility of the energy harvesting isolation system has been investigated through the numerical simulation.

특집 : 증권사랑방 ; 주제1: 사모펀드, 약인가 독인가

권성철 한국증권학회 2008 한국증권학회보 Vol.68 No.-

의탄성 형상기억합금 메쉬 와셔가 적용된 수동형 진동절연기의 수학적 등가모델 도출

권성철,전수현,오현웅,Kwon, Sung-Cheol,Jeon, Su-Hyeon,Oh, Hyun-Ung 항공우주시스템공학회 2014 항공우주시스템공학회지 Vol.8 No.3

A passive launch and on-orbit vibration isolator using SMA(Shape Memory Alloy) washer for both the structural safety of the micro-vibration source by attenuating the transmitted force under launch loads and the micro-vibration isolation during their on-orbit operation has been proposed, which does not require the additional launch locking mechanism. To measure the characteristics of SMA mesh washer, we performed compressive loading tests with a single SMA mesh washer and a vibration isolator using SMA mesh washer. The numerical equivalent model of vibration isolator using SMA mesh washer composed of two spring and viscous damping elements has been verified that both stiffness and viscous damping varied with respect to compressed deformations. In addition, the effectiveness of launch loads and micro-vibration reduction has been investigated through the dynamic characteristics measurement test of cooler assembly combined with passive vibration isolator.

쿨러 미소진동의 전기에너지로의 재생 및 진동절연을 위한 동 흡진기형 하베스터의 기본성능 검토

권성철,안주훈,조문신,오현웅 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.11

서지유발 동기화 스위칭 기법을 통한 미소진동 에너지 수확의 유효성 검토

권성철,오현웅 항공우주시스템공학회 2017 항공우주시스템공학회 학술대회 발표집 Vol.2017 No.11