다구찌 방법에 의한 유리-실리콘 양극접합 계면의 파괴인성치 측정 및 양극접합공정 조건에 따른 접합강도 분석

강태구,조영호,Kang, Tae-Goo,Cho, Young-Ho 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.6

Anodic bonding process has been quantitatively evaluated based on the Taguchi analysis of the interfacial fracture toughness, measured at the interface of anodically bonded silicon-glass bimorphs. A new test specimen with a pre-inserted blade has been devised for interfacial fracture toughness measurement. A set of 81 different anodic bonding conditions has been generated based on the three different conditions for four different process parameters of bonding load, bonding temperature, anodic voltage and voltage supply time. Taguchi method has been used to reduce the number of experiments required for the bonding strength evaluation, thus obtaining nine independent cases out of the 81 possible combinations. The interfacial fracture toughness has been measured for the nine cases in the range of 0.03∼6.12 J/㎡. Among the four process parameters, the bonding temperature causes the most dominant influence to the bonding strength with the influence factor of 67.7%. The influence factors of other process parameters, such as anodic voltage and voltage supply time, bonding load, are evaluated as 18%, 12% and 2.3%, respectively. The maximum bonding strength of 7.23 J/㎡ has been achieved at the bonding temperature of 460$\^{C}$ with the bonding load of 45gf/㎠, the applied voltage of 600v and the voltage supply time of 25minites.

논문 : 배당의 미래이익 예측력과 외국인투자자

강태구 ( Tae Goo Kang ),이창우 ( Chang Woo Lee ),남혜정 ( Hye Jeong Nam ) 명지대학교 금융지식연구소 2013 금융지식연구 Vol.11 No.3

본 연구는 배당의 미래이익 예측력이 외국인 투자자들의 지분율에 따라 어떻게 달라지는지 검증하였다. 일반적으로 배당지급은 기업의 미래이익을 예측하는 데 유용한 정보로 여겨지고 있으나, 이에 대한 실증연구결과들은 혼재되어 있다. 또한 배당의사결정과 관련된 연구들은 투자자들의 배당선호현상에 따라 기업의 배당의사결정이 영향을 받고 있음을 제시하고 있으며, 특히 우리나라의 경우, 배당의사결정에 외국인투자자가 미치는 영향이 매우 높게 나타나고 있다. 이는 특정투자자집단의 배당요구가 높은 경우, 기업의 배당의사결정이 미래이익에 대한 사적정보의 전달수단이기 보다는 단기적으로 배당에 대한 투자자들의 요구를 반영한 결과로 나타날 수 있음을 보여준다. 나아가 이러한 배당의사결정은 배당의 미래이익 예측력을 낮게 만들 것으로 예측된다. 본 연구는 배당의 미래이익 예측력을 재검증하고, 나아가 외국인지분율에 따라 배당의 미래이익예측력이 달라지는지 검증하였다. 먼저, 배당의 미래이익 예측연구들은 자기자본이익률(ROE)의 평균회귀(mean reverting)현상과 배당증가 또는 배당감소가 이익변화에 미치는 비대칭적 영향을 고려하고 있으나, 이익변화에 영향을 미치는 여러 가지 변수들을 통제하지 않고 있다. 따라서 본 연구는 선행연구에서 제시되고 있는 기업규모(SIZE), 성장성(SGR), 부채비율(LEV), 그리고 연도더미를 추가하여, 이를 통제하고 난 후에도 배당의 미래이익예측력이 여전히 존재하는지 검증하였다. 둘째, 배당의 미래이익 예측력이 기업의 배당의사결정에 영향을 미치는 특정집단에 의하여 달라지는지 검증하였다. 2000년부터 2007년까지 배당지급을 한 6,720 기업-년 표본을 대상으로 분석한 결과, 기본 모형뿐만 아니라 여러 통제변수를 포함한 모형에서도 우리나라 기업들의 배당변화는 미래 1년 뒤의 이익변화와 유의한 양의 관계를 나타냈으나, 미래 2년 뒤의 이익변화와는 유의하지 않았다. 또한 이익변화에 영향을 미치는 변수들을 추가한 모형의 설명력(R2=0.46)이 기본모형의 설명력(R2=0.28)보다 급격히 증가함을 알 수 있었다. 그러나 이러한 관계는 외국인지분율을 통제할 경우, 유의하지 않게 나타났다. 이는 기업의 배당의사결정이 미래전망에 근거하여 이루어지기보다는 특정투자자집단의 배당요구를 반영하는 수단으로 사용되고 있음을 보여준다. 즉 우리나라의 경우, 배당의사결정이 외국인투자자들의 배당요구를 반영하여 이루어짐을 알 수 있다. 본 연구는 대부분의 선행연구들이 외국인투자자와 배당성향간의 동시적인 관계에 대한 결과들을 제시한 반면에, 외국인투자자가 우리나라 기업들의 배당의사결정에 미치는 영향과 함께 배당의 미래이익예측력의 관점에서 살펴보았다는 점에 의의가 있다. This paper investigates whether the dividend payout predicts future earnings and the predictability varies depending on the proportion of investors. Specifically, this paper examines the effect of foreign investors on the relationship between dividend change and the predictability of future earnings in Korean firms. Reasoning from the hypothesis that dividend changes convey new information about a firm`s future profitability, a dividend increase is seen as a positive signal about the firm`s future earnings and profitability. However, the results from prior studies are controversial. Some papers have suggested that dividend changes would mean different things depending on a firm`s dividend policy and the motives behind its managers` decision to pay dividends. In addition, a firm`s governance is considered as one of important factors that affects dividend policy. In the Korean security market, foreign investors owned about 38% of the stock in 2007. As the percentage of foreign ownership had grown, many researchers have analyzed the effect of this ownership on dividend policy. However, prior studies found mixed results and have focused on the association between foreign investors and the level of the dividend or dividend change. They also suggest that predictability of dividend on future earnings is influenced by applied assumption on earnings and other factors like governance as well. We revisit the dividend signaling issue in the light of the catering theory of dividends suggested by Baker and Wurgler (2004). Lintner (1956) argued that managers unwilling to change payout ratio without any important change on the firm`s future performance. Won and Kim (1992) report that managers are more likely to be concerned about the internal factors such as net income, divisible surplus, predicted future performance, and the shareholders` preference for dividend policy. More importantly, several studies suggest that the foreign investors have a significant effect on the Korean market. Park (2004) reports that foreign investors` participation in firms generally pushes up the dividend payments while pulling down investments made in facilities no matter which industry a company is in. Sul and Kim (2006) show that those companies whose majority shareholders are foreign investors tend to pay higher dividends than others whose majority shareholders are domestic investors. In contrast to negative effect of foreign investor, there are empirical studies claiming positive impact of foreign investor in Korean market. Ahn, Shin, and Chang (2005) suggest that foreign investors prefer firms with lower information asymmetry. The study also shows that foreign investors can effectively monitor the management of firm in lessening information asymmetry. Similarly, Park and Lee (2006) suggest that foreign investors` participation in investment of domestic firms can help them make more efficient management decision by improving their corporate governance. Thus, Park and Lee claim that it is problematic to generalize the negative role of foreign investors in the Korean market. Based on this argument, we predict that if foreign investors play an effective monitoring role in a dividend policy, dividend change for firms with higher level of foreign investors is a good indicator in predicting future earnings than for firms with lower level of foreign investors. However, if foreign investors play a negative role in dividend decision process, predictability of dividend decreases. We test this prediction by using the modified model with several control variables that can affect earnings changes. Using 6,720 observations from 1993 to 2007, we find that the dividend change predicts future earnings for next one year relative to the dividend change year. Specifically, the coefficient on RDIV is 0.045 (t=6.85) and this indicates the dividend increases is a good indicator in predicting future earnings. When it comes to model specification, adjusted R2 of modified model is greater than that of the basic model, which means that the modified model is well specified in explaining earnings changes. The result of the effect of foreign investors on predictability of dividend is not significant. This finding implies that managers, on average, decide to pay dividend as a response to demand from foreign investors.

저온 비등 팽창유체와 고점성 유체마개를 이용한 고출력 저전력형 마이크로 분사기

김상욱,강태구,조영호,Kim, Sang-Wook,Kang, Tae-Goo,Cho, Young-Ho 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.6

A high-impulse, low-power, digital microthruster has been developed using low-boiling-temperature liquid propellant with high-viscosity fluid plug. The viscous fiction force of the fluid plug increases the blast pressure and the low-boiling-temperature liquid propellant is intended to reduce input power consumption. The three-layer microthruster has been fabricated by surface micromachining as well as bulk micromachining in the size of 7$\times$13$\times$1.5㎣. A digital output impulse bit of 6.4$\times$10$^{-8}$ Nsec has been obtained from the fabricated microthruster using perfluoro normal hexane (FC72) propellant and oil plug, resulting in about ten times increase of the impulse bit using one hundredth electrical input energy compared to the conventional multiple-shot microthruster.

MDGHM와 new energy function을 적용한 강회된 SIFT flow

백경구(Kyung-Goo Paek),강태구(Tae-Koo Kang),임묘택(Myo-taeg Lim) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.10

MDGHM와 new energy function을 적용한 강회된 SIFT flow

백경구(Kyung-Goo Paek),강태구(Tae-Koo Kang),임묘택(Myo-taeg Lim) 대한전기학회 2013 정보 및 제어 심포지엄 논문집 Vol.2013 No.10

Development of Wireless Monitoring System for Distribution Transformer

정준홍(Joon-Hong Jung),강태구(Tae-Goo Kang),김일경(Il-Kyung Kim) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.7

Development of Wireless Monitoring System for Distribution Transformer

정준홍(Joon-Hong Jung),강태구(Tae-Goo Kang),김일경(Il-Kyung Kim) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.7(초록집)

DoD 메탈젯 프린팅 시스템

이택민(Taik-Min Lee),강태구(Tae Goo Kang),양정순(Jeong-Soon Yang),조정대(Jeong-Dai Jo),김광영(Kwang-Young Kim),최병오(Byung-Oh Choi),김동수(Dong-Soo Kim) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.8

용융 메탈 잉크젯 시스템

이택민(Taik-Min Lee),강태구(Tae Goo Kang),양정순(Jeong-Soon Yang),조정대(Jeong-Dai Jo),김광영(Kwang-Young Kim),김동수(Dong-Soo Kim) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

In this paper, we present a design, analysis, fabrication and performance test of the novel DoD metal-jet system for application to the high-density and high-temperature-melting materials. Based on the theoretical analysis, we design the metal-jet print head system and fabricate the metal-jet system, which can eject the droplet of lead-free metal solder in the high-temperature. In the experimental test, we set up the test apparatus for visualization of the droplet ejection and measure the ejected droplet volume and velocity. As a result, the diameter, volume and the velocity of the ejected droplet are about 65-70㎛, 145-180 pl and 4m/sec. We also fabricate vertical and inclined 3D micro column structures using the present molten metal inkjet system. The measured geometries of the micro column structures are about height of 2,100㎛, diameter of 200㎛ and aspect ratio of 10.5 for vertical micro column and 1,400㎛ of height and 150㎛ of diameter for 65°- inclined micro column, respectively.

DoD 메탈젯 시스템의 이론적 해석

이택민(Taik-Min Lee),강태구(Tae Goo Kang),양정순(Jeong-Soon Yang),조정대(Jeong-Dai Jo),최병오(Byung-Oh Choi),김광영(Kwang-Young Kim),김동수(Dong-Soo Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

We present a design, analysis, fabrication and performance test of the novel DoD metal-jet system for application to the high-density and high-temperature-melting materials. The theoretical analysis of the metaljet nozzle system is derived by using electro-mechanical analogy. Based on the theoretical analysis results, we design the metal-jet print head system and fabricate the metal-jet system, which can eject the droplet of leadfree metal solder in high-temperature. In the experimental test, we set up the test apparatus for visualization of the droplet ejection and measure the ejected droplet volume and velocity. As a result, the diameter, volume and the velocity of the ejected droplet are about 65 ㎛ ~ 70 ㎛, 145pl ~ 180 pl and 4m/sec, which shows quite good agreement with the theoretical analysis results of the 75 ㎛-diameter and 220 pl-volume of droplet. In comparison with the experimental result, the errors of diameter and volume are 7% ~ 13% and 18 ~ 34%, respectively.