• 제목/요약/키워드: Leading Journal

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Business Strategy and Overvaluation: Evidence from Korea

  • CHA, Sangkwon;HWANG, Sunpil;KIM, Yibae
    • The Journal of Asian Finance, Economics and Business
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    • 제6권4호
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    • pp.83-90
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    • 2019
  • The purpose of this study is to test the effect of business strategy on valuation error. Business strategy includes managerial decision making and managerial tendency. In previous research, there is a negative relationship between business strategy and accounting quality. In this study, we try to confirm whether strategy tendencies affected valuation errors. In order to confirm empirically between business strategy and overvaluation, we use 8,117 firms that between 2006 and 2017 and listed in KSE and KOSDAQ. We calculated business strategy which is introduced by Bentley, Omer, and Sharp (2013). We also used the overvaluation method introduced in Rhodes-Kropf, Robinson, and Viswanathan (2005). The results show that the more the leading business strategy is, the greater the value error becomes. In the case of dividing into leading and defensive companies, the lead firms showed a significant positive correlation with the valuation errors, while the defensive firms showed the negative relationship with overvaluation. This study examined the business strategy and the overvaluation. we confirmed whether the management strategy deepens the evaluation error caused by the firm characteristics. The results are meaningful that we extended the study on the quality of financial reporting of leading strategic firms.

연장된 앞전을 갖는 델타형 날개에서의 와류 상호작용에 관한 연구 (Investigation of Vortex Interactions over a Delta Wing with the Leading Edge Extension)

  • 이기영;손명환;장영일
    • 한국군사과학기술학회지
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    • 제4권2호
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    • pp.215-224
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    • 2001
  • An experimental investigation was conducted on the interaction of vortices over a delta wing with the leading edge extension for three angles of attack($16^{\circ},\; 24^{\circ} \;and\; 28^{\circ}$) at Reynolds number of $1.76{\times}10^6.$ The experimental data included total pressure contours and velocity vectors using 5-hole probe measurements. Constant total pressure coefficient contours show the LEX vortex moves downward and outboard, while the wing vortex exhibited an inboard and upward migration. At near the trailing edge, these vortices reveal a direct interaction between the wing and LEX vortex, featuring a coiling of vortex cores about each other. The combined effect of the interaction of these two vortices and proximity to the wing surface results in the increase of the suction peak. This is in contrast to the result obtained on the delta wing alone configuration, where the effect of the vortex breakdown was manifested. The interaction of the wing and LEX vortices is more pronounced at higher AOA.

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우리나라와 노르웨이의 선망어업 현황 및 생산구조 비교 (Comparison of Production Structure of Purse Seine Fishery in Korea and Norway)

  • 김대영
    • 수산해양교육연구
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    • 제27권1호
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    • pp.308-318
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    • 2015
  • In order to improve the competitiveness of Korean large purse seine fishery, the purpose of this study is to find out the problems and present the improvement of the production structure of Korean large purse seine fishery by comparing to the production structure of Norwegian purse seine fishery. Norwegian purse seine fishery has been operating labor and energy-saving systems through a single wire operation and avoiding fishing competition through the introduction of IVQ system with different types of fishing vessel and obtaining benefits from Leading fishery management integrated with fish pumps and cooling water systems. In contrast, our country has a large purse seine fishery issues such as high cost and low efficiency of production structures, the volatility of mackerel resources, the lack of leading fishery management after catching fishes, the reduction of fishing ground in accordance with the North East Asia EEZ system. To solve these problems, initiatives to improve the structure of our large purse seine fishery are as follows: First, Implementing the promotion of the effective immature fishes management and establishing Korea-China-Japan resource management system. Second, the promotion of reduction of fleet size, the review of possible single fishing operation, leading out to strengthen its competitiveness by switching to energy-efficient production systems through enhanced efforts at fisheries catches steps. Third, it is necessary to realize corporate through the diversification of business areas and the large-scale commercialization of production structure.

에너지절약을 위한 상호련결된 반보호좌회전 교차로의 신호시간설계 (Traffic Signal Timing at Interconnected and Semi-Protected-Left-Turn Intersections for Energy Saving)

  • 김경환
    • 대한교통학회지
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    • 제8권1호
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    • pp.25-40
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    • 1990
  • This study was undertaken to develop a traffic signal timing method for interconnected and semi-protected-left-turn intersections(the intersections which have left-turn signal but not exclusive left-turn lanes) on four-lane streets for energy saving and to computerize the method for the practical use. For this study, a probability model which could estimate the utilized time of the shared left-turn lane by through traffic during green period was developed based on field studies. The two left-turn treatments, leading and lagging left-turns, were tested for the intersections, and it can be concluded that the leading left-turn was more efficient for the normal urban streets on which through traffic is major traffic. Adopting the leading left-turn macro-models to estimate vehicular average delay and proportions of vehicles stopped at the intersections were developed. Using the two models as well as the idling fuel consumpution rate and the excess fuel consumption per stop-go speed change, a traffic signal timing method for the intersections for energy saving was developed and computerized. The method can be used for more than four-lane streets and for other measures of effectiveness such as minimum delay, minimum stop rates, etc.

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합성제트를 이용한 타원형 익형 유동제어 (FLOW CONTROL ON ELLIPTIC AIRFOILS USING SYNTHETIC JET)

  • 김성훈;김철완
    • 한국전산유체공학회지
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    • 제15권4호
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    • pp.46-52
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    • 2010
  • In the present work, the aerodynamic characteristics of elliptic airfoils which have a 12% thickness ratio are numerically investigated based on Reynolds-averaged Navier-Stokes equations and a transition SST model at a Reynolds number 8.0$\times$105. The numerical simulation of a synthetic jet actuator which is a well-known zero-net-mass active flow control actuator located at x/c = 0.00025, was performed to control massive flow separation around the leading edge of the elliptic airfoils. Four cases of non-dimensional frequencies were simulated at an angle of attack of 12 degree. It is found that the size of the vortex induced by synthetic jets was getting smaller as the jet frequency becomes higher. Comparison of the location of synthetic jets between x/c = 0.00025 (around the leading edge) and x/c = 0.9 (near the separation) shows that the control near the leading edge induces closed recirculation flow regions caused by the interaction of the synthetic jet with the external flow, but the control applied at 0.9c (near the trailing edge) induces a very small and weak vortex which quickly decays due to weak intensity.

축류 압축기 블레이드 손상시 터빈부품에 미치는 영향 (Effects of the Damaged Axial-flow Compressor Blade on the Gas Turbine Components)

  • 강명수;윤완노;김계연
    • 동력기계공학회지
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    • 제11권3호
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    • pp.53-58
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    • 2007
  • The ruptured blade which is rotating at high speed can damage severely the all stage compressor blades and the turbine components. If the shattered blades flow downstream inside the turbine parts, then the turbine blades and vanes can be damaged. The small parts of shattered blades which are flowed into the turbine parts pass through without any damages in the leading edge of the first stage stationary blades. Then they bump against the convex side of the leading edge of the first stage moving blades and the trailing edge of the first stage stationary blades repeatedly. The debris of shattered blades may plug the cooling holes in the turbine blades and vanes. The dent damage and the coating delamination could be also occurred by the debris of shattered blades flowed downstream inside the combustion liner and the transition piece. This paper analyzes the influence on the turbine components and the damage mechanism and characteristics in case of the damaged blade of the multiple-stage axial flow compressor.

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동하중을 받는 구조물의 손상해석을 위한 대형균열모형과 수치 알고리즘 (Large Crack Model and Its Numerical Algorithm for Damage Analysis of Dynamically Loaded Structures)

  • 이지호
    • 한국지진공학회논문집
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    • 제9권6호
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    • pp.59-65
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    • 2005
  • 본 논문에서는 기존 연속균열모형들이 대형균열 표현에서 소성변형을 과도하게 계산하는 문제점을 극복한 대형균열모형을 제안하였다. 또한 소성손상모형을 수정한 형태로 제안된 균열모형을 수치해석에 사용할 수 있도록 3단계 회귀매핑 알고리즘으로 구성된 알고리즘을 제시하였다. 전산해석 예제들을 통하여 제안된 균열손상 모형과 알고리즘이 동적 하중을 받는 구조물의 균열해석문제에서 과도한 소성변형을 억제하는 합리적인 결과를 도출함을 알 수 있었다.

THE FUNDAMENTAL SHOCK-VORTEX INTERACTION PATTERNS THAT DEPEND ON THE VORTEX FLOW REGIMES

  • Chang, Keun-Shik;Barik, Hrushikesh;Chang, Se-Myong
    • 한국전산유체공학회지
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    • 제14권3호
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    • pp.76-85
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    • 2009
  • The shock wave is deformed and the vortex is elongated simultaneously during the shock-vortex interaction. More precisely, the shock wave is deformed to a S-shape, consisting of a leading shock and a lagging shock by which the corresponding local vortex flows are accelerated and decelerated, respectively: the vortex flow swept by the leading shock is locally expanded and the one behind the lagging shock is locally compressed. As the leading shock escapes the vortex in the order of microseconds, the expanded flow region is quickly changed to a compression region due to the implosion effect. An induced shock is developed here and propagated against the vortex flow. This happens for a strong vortex because the tangential flow velocity of the vortex core is high enough to make the induced-shock wave speed supersonic relative to the vortex flow. For a weak shock, the vortex is basically subsonic and the induced shock wave is absent. For a vortex of intermediate strength, an induced shock wave is developed in the supersonic region but dissipated prematurely in the subsonic region. We have expounded these three shock-vortex interaction patterns that depend on the vortex flow regime using a third-order ENO method and numerical shadowgraphs.

소형 액체 로켓 엔진에서의 점화 시퀀스 결정 및 인젝터 수명 연장 기법 평가 (Determination of Ignition Squence and Estimation of Injector Life Extension Technique in Liquid Rocket Engine)

  • 박정;김용욱;김영한;문일윤;이재룡;강선일;정용갑;조남경;오승협
    • 한국연소학회지
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    • 제5권1호
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    • pp.43-53
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    • 2000
  • Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignition process with liquid rocket engine. The propellant used is a Jet A-1 as fuel and a liquid oxygen as oxidizer. Unlike impinging FOOF type of injectors are arranged radially and the designed O/F ratio is 2.34. The present experiment program also includes the stability on the quadlet type of ignitor using the triethylalumimum as an ignition source and injector life tests. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time of propellants affects the engine performance little. The effect of positioning cooling holes is remarkable to protect the injector face.

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Acceptance of Smart Clothing Based on Outdoor Consumption Behavior

  • Cho, Hakyung;Lim, Ho-sun
    • 한국의류산업학회지
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    • 제22권2호
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    • pp.209-221
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    • 2020
  • Recently, following the commercialization and market entry of smart clothes with diverse functions, smart clothes have been changing from technology-centered products to user-centered products. However, the analysis of consumer demand centered on actual commercialized products is lacking. Therefore, this study classified commercialized smart clothes by function and analyzed the demand and requirements of smart clothes according to sports/outdoor clothes consumption behaviors. As a result, consumers were classified according to their sports/outdoor clothes consumption behaviors into an outdoor leading group with high consumption propensity, an outdoor pursuit group with medium consumption propensity, and an outdoor following group with low consumption propensity. Among the commercialized smart clothes, those with a heartbeat measuring function, those with a heating function, and those with a light-emitting function were presented and demand analysis was conducted. According to the results, the outdoor leading group and the outdoor pursuit group had higher levels of awareness, preference, and purchase intentions than the outdoor following group. In addition, the outdoor leading group showed the highest level of purchase price acceptance while the outdoor following group showed the lowest level of purchase price acceptance. However, this study has a limitation that the acceptance for smart clothes were analyzed with consumers who had experience in sports outdoor clothes consumption. Therefore, in future, studies will be conducted with a wide range of consumers.