• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.665-667
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• 2013

Metal ions show various transitions in the cathode of a lithium-ion battery. The diffusion process of lithiumions and the phase transition in the cathode need to be thoroughly understood for the advanced design of an improved lithium-ion battery. Here, we employ a phase field model to simulate the diffusion of lithiumions and to study the phase transition in the cathode.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.1
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• pp.85-95
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• 2016

Generally a venture capital aims at investment and support Venture businesses that signifies a start-up which has high technologies but frailty of the economy so that raise fund from financial agencies at high risk rate, it has high risk but when the venture businesses launch into general orbit, the venture capital guarantee high-rate profits. Venture capital do not just provide risk capital but also takes a role as a mentor for continuous growth with total consulting service at business and technical management. Also it offers in-depth support to reform the supported enterprise in order to enhance the competitive. Venture capital receives attention for years as a principal agent to be promoted strategically at national level. Bio venture, a major concern of venture capital and one of core industries in Korea, is different from other industries because it needs long-term and large scale of investment. these factors bring about difficulties in an investment and growth. Therefore, it is very important to identify growth and profitability of start-ups and small and venture businesses with long-term appreciation above all other industries. This research analyze management results of bio venture businesses empirically by investment from venture capital. according to the results, bio venture businesses need huge capital and a long gap of time, henceforth, formation of model for growth is necessary with angel investing as well as venture capital. Since, there are not many listed bio venture businesses, significant statistical result would be limited. This research studied at only economic focus but further study need to examine a question from various angles.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.51-60
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• 2021

In this study, Based on the analysis of the correlation between internal control quality and earnings management, this article discusses the correlation between internal control quality and real activity earnings management and accrued earnings management. For this study, by introducing the concept, classification, measurement method and model of internal control and earnings management, the research hypothesis of this article was proposed. In this analysis, Use the relevant measurement model to calculate the actual activity earnings management level and accrued earnings management level of the enterprise, as the explained variable, establish a model for regression and were analyzed. Also, this study could find the final results draws a conclusion through empirical research: there is a significant negative correlation between the internal control quality of listed companies, real activity earnings management, and accrued earnings management. On the basis of this conclusion, the analysis of possible causes provides a basis for the development of internal control theory and the supervision and control of earnings management behavior in the future.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.15-18
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• 2000

본 논문은 중규모 어휘인 1500여 단어 실시간 화자 독립 단독어 음성인식 시스템에 대해서 기술한다. 음향 모델은 HMM을 이용하였으며, 음소 모델은 문맥종속 모델인 트라이폰을 사용하였다. 이 시스템은 텍스트로부터 쉽게 사전을 구성할 수 있는 유연성을 갖는다. 선정된 단어는 주식시장에 상장되어 있는 1456개의 회사명으로 비교적 혼동하기 쉬운 단어들을 많이 포함한 사전이다. 실시간 처리를 위한 알고리즘들 중 인식율을 크게 저하시킬 가능성이 있는 기법들은 제외하였다. 여기에 트리 빔과 음소 빔을 적용하면서 topN을 적용하였으며 새로운 스코아 캐쉬 기법을 고안하였다. 특별히 스코아 캐쉬 기법은 인식율에는 전혀 영향을 미치지 않으면서 계산량을 $38\%$나 줄여주었다. 이런 기법들을 적용하여 실시간 음성인식을 구현할 수 있었다. Intel 450M CPU가 장착되어 있는 리눅스 시스템에서 평균 1.98초의 응답 시간을 보였다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.318-321
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• 2009

Transformation plasticity is that when a phase transformation of ferrous or non-ferrous alloys progresses even under an extremely small applied stress compared with a yield stress of the material, a permanent deformation occurs. One of widely accepted description for the transformation was proposed by Greenwood and Johnson [1]. Their description is based on an assumption that a weaker phase of an ideal plastic material could deform plastically to accommodate the externally applied stress and the internal stress caused by the volumetric change accompanying the phase transformation. In this study, an implicit finite element model was developed to simulate the deformation behavior of a low carbon steel during phase transformation. The finite element model was coupled with a phase field model, which could simulate the kinetics for ferrite to austenite transformation of the steel. The thermo-elasto-plastic constitutive equation for each phase was adopted to confirm the weaker phase yielding, which was proposed by Greenwood and Johnson [1]. From the simulation, the origin of the transformation plasticity was quantitatively discussed comparing with the other descriptions of it.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.589-594
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• 2014

Recently, higher capacity and energy density of lithium ion batteries are increasingly demanded for enhancing their performance in view of the rise in the commercial distribution of electric and hybrid vehicles. Computational analysis of a porous structure of vanadium pentoxide cathode was performed, employing a phase field model. The incipient model was designed as a spherical structure with cylindrical-shaped pores. Modifying the diameters and lengths of the pore cylinder and the number of pores, we considered different conditions for the porous vanadium pentoxide cathodes for analyzing their effect on the amount of lithium ion intercalated to them. Subsequently, we optimized the porous structure to contain the largest amount of intercalated lithium ion during discharge.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.131-144
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• 2020

Political connection are widespread in many countries and are a hot topic in economic research right now. In China, companies are actively forming political connections in several ways. Based on the research model and theoretical analysis, this thesis puts forward the research hypothesis and constructs the research model of political connections and corporate performance using the financial data and corporate governance data of China A-share listed real estate companies in 2010-2014. The thesis mainly analyzes the political association of CEO. For the analysis result, this research uses the univariate regression analysis and multivariate analysis to carry out the robustness test. The empirical study analysis includes three parts: firstly, in Chinese listed real estate enterprises, CEO political connection has a significantly negative correlation with corporate performance. It means real estate enterprises whose CEO has political connections gain a lower performance than other enterprises; Secondly, from the personal characteristics of the CEO, age, sex and education level have positive relationship with the performance of the enterprise, the additional post situation negatively related to the firm's performance; Finally, the firm's scale liquidity ratio and capital asset rario have a negative relationship with corporate performance, and the number of top managers is positively related to corporate performance. This research made a study on the political connection in Chinese real estate industry, which could also provide beneficial references for the development of enterprises in this industry.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.217-219
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• 2000

도시기온분포에 영향을 미치는 요인은 매우 복잡하기 때문에 최근 세부적인 도시열환경 분포현황을 파악하기 위해서 국지규모 모델을 이용하여 그 사례를 밝히고 있다. 도시의 열환경구조가 land use와 밀접한 관련이 있다는 것은 이미 밝혀진 사실이나 보다 상세 격자를 이용한 도시지역의 열환경구조를 land use와 관련지어 연구 분석한 사례는 국내에서 거의 없는 실정이다. 즉, 국지지역의 열환경변화를 묘사하기 위해서는 종관기상장과 관련된 초기 및 경계조건 결정의 문제점을 해결하기 위한 다중격자체계의 모델 사용이 요구되는 실정이다. (중략)

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.187-191
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• 2001

본 논문의 목적은 안전성과와 경영성과의 영향관계를 체계적으로 설명할 수 있는 모형을 개발하고, 근로자수 300인 이상인 기업 43개와 300인 미만인 30개 기업을 구분해서 개발한 모형을 실증적으로 분석함으로써 모델의 타당성을 분석하는데 있다. 안전성과에 대한 변수는 노동부산하의 한국산업안전공단에서 집계한 재해자 수와 근로손실일 수를 선정하였으며, 경영성과에 대한 자료는 (주)한국신용정보와 (주)매일경제에서 출간하는 상장기업분석자료를 근거로 하여 1인당매출액을 선정하고 조절변수로 사용된 노무비, 경비, 부채비율, 수출비중을 업계평균에 비해 상대적으로 높고 낮은 정도를 높은 기업은 1, 낮은 기업은 0의 값을 지정하여 실증분석을 실시하였다. 이를 통하여 기업의 특성요인들에 따라 안전성과가 경영성과에 미치는 영향이 다르다는 본 연구의 이론적 모델은 근로자 수가 300인 이상인 국내 대기업의 경우에는 그 타당성을 지닌다고 볼 수 있었다.

• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.95-120
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• 1990

The underpricing of new shares of a firm that are offered to the public for the first time (initial offerings) is well known and has puzzled financial economists for a long time since it seems at odds with the optimal behavior of the owners of issuing firms. Past attempts by financial economists to explain this phenomenon have not been successful in the sense that the explanations given by them are either inconsistent with the equilibrium theory or implausible. Approaches by such authors as Welch or Allen and Faulhaber are no exceptions. In this paper, we develop a signalling model of capital investment to explain the underpricing phenomenon and also analyze the efficiency of investment. The model focuses on the information asymmetry between the owners of issuing firms and general investors. We consider a firm that has been owned and operated by a single owner and that has a profitable project but has no capital to develop it. The profit from the project depends on the capital invested in the project as well as a profitability parameter. The model also assumes that the financial market is represented by a single investor who maximizes the expected wealth. The owner has superior information as to the value of the firm to investors in the sense that it knows the true value of the parameter while investors have only a probability distribution about the parameter. The owner offers the representative investor a fraction of the ownership of the firm in return for a certain amount of investment in the firm. This offer condition is equivalent to the usual offer condition consisting of the number of issues to sell and the unit price of a share. Thus, the model is a signalling game. Using Kreps' criterion as the solution concept, we obtained an essentially unique separating equilibrium offer condition. Analysis of this separating equilibrium shows that the owner of the firm with high profitability chooses an offer condition that raises an amount of capital that is short of the amount that maximizes the potential profit from the project. It also reveals that the fraction of the ownership of the firm that the representative investor receives from the owner of the highly profitable firm in return for its investment has a value that exceeds the investment. In other words, the initial offering in the model is underpriced when the profitability of the firm is high. The source of underpricing and underinvestment is the signalling activity by the owner of the highly profitable firm who attempts to convince investors that his firm has a highly profitable project by choosing an offer condition that cannot be imitated by the owner of a firm with low profitability. Thus, we obtained two main results. First, underpricing is a result of a signalling activity by the owner of a firm with high profitability when there exists information asymmetry between the owner of the issuing firm and investors. Second, such information asymmetry also leads to underinvestment in a highly profitable project. Those results clearly show the underpricing entails underinvestment and that information asymmetry leads to a social cost as well as a private cost. The above results are quite general in the sense that they are based upon a neoclassical profit function and full rationality of economic agents. We believe that the results of this paper can be used as a basis for further research on the capital investment process. For instance, one can view the results of this paper as a subgame equilibrium in a larger game in which a firm chooses among diverse ways to raise capital. In addition, the method used in this paper can be used in analyzing a wide range of problems arising from information asymmetry that the Korean financial market faces.