돼지 지방 조직 및 골수 유래 성체줄기세포의 성상분석과 다능성에 관한 연구

이아영,최경임,나진주,소병재,이경우,장기윤,송재영,차상호,Lee, Ah-Young,Choe, Gyeong-Im,Nah, Jin-Ju,So, ByungJae,Lee, Kyung-Woo,Chang, Ki-Yoon,Song, Jae-Young,Cha, Sang-Ho 대한수의학회 2013 大韓獸醫學會誌 Vol.53 No.1

Mesenchymal stem cells (MSCs) have ability to differentiate into multi-lineage cells, which confer a great promise for regenerative medicine to the cells. The aim of this study was to establish a method for isolation and characterization of adipose tissue-derived MSC (pAD-MSC) and bone marrow-derived MSC (pBM-MSC) in pigs. Isolated cells from all tissues were positive for CD29, CD44, CD90 and CD105, but negative for hematopoietic stem cell associated markers, CD45. In addition, the cells expressed the transcription factors, such as Oct4, Sox2, and Nanog by RT-PCR. pAD-MSC and pBM-MSC at early passage successfully differentiated into chondrocytes, osteocytes and adipocytes. Collectively, pig AD-MSC and BM-MSC with multipotency were optimized in our study.

종자결정을 활용한 다결정 규소 잉곳 내의 구조적 결함 규명

이아영,김영관,Lee, A-Young,Kim, Young-Kwan 한국결정성장학회 2014 한국결정성장학회지 Vol.24 No.5

Because of the temperature gradient occurring during the growth of the ingot with directional solidification method, defects are generated and the residual stress is produced in the ingot. Changing the growth and cooling rate during the crystal growth process will be helpful for us to understand the defects and residual stress generation. The defects and residual stress can affect the properties of wafer. Generally, it was found that the size of grains and twin boundaries are smaller at the top area than at the bottom of the ingot regardless of growth and cooling condition. In addition to that, in the top area of silicon ingot, higher density of dislocation is observed to be present than in the bottom area of the silicon ingot. This observation implies that higher stress is imposed to the top area due to the faster cooling of silicon ingot after solidification process. In the ingot with slower growth rate, dislocation density was reduced and the TTV (Total Thickness Variation), saw mark, warp, and bow of wafer became lower. Therefore, optimum growth condition will help us to obtain high quality silicon ingot with low defect density and low residual stress. 방향성 응고법으로 잉곳을 성장시킬 때 발생하는 온도 구배에 의해 잉곳 내에 결함이 생성되고 잔류 응력이 남게 된다. 이 결함과 잔류 응력은 잉곳의 성장 조건에 따라 달라지며, 웨이퍼의 특성에 큰 영향을 미칠 수 있다. 성장 속도의 변화에 상관 없이 대부분의 잉곳에서는 하부 영역에 비해 상부 영역에서 결정립과 쌍정경계의 크기가 작았으며, 결정립계뿐만 아니라 결정립 내에도 전위 밀도가 높았다. 이것은 상부 영역에서 성장 중에 받는 열 응력이 하부 영역보다 크다는 것을 암시한다. 두 잉곳 간의 차이를 보았을 때에는 성장 속도가 느린 잉곳에서 전위 밀도가 감소하였으며, 웨이퍼의 평탄도, 뒤틀림, 휨, 절단자국이 낮게 측정되었다. 따라서 다결정 성장 공정에서는 냉각 속도가 결함이나 잔류 응력의 발생에 미치는 영향이 크며, 그로 인하여 웨이퍼의 특성이 달라지는 것을 알 수 있었다.

태양전지용 규소 결정 성장 기술 개발의 현황

이아영,이동규,김영관,Lee, A-Young,Lee, Dong-Gue,Kim, Young-Kwan 한국결정성장학회 2014 韓國結晶成長學會誌 Vol.24 No.2

태양전지용 규소에는 단결정, 다결정, mono-like의 세 가지 재료가 사용 중에 있다. 첫 번째로, 단결정은 수율향상의 과제에 집중되고 있으며, 이것은 고액 계면의 형상이 주요 요인으로 알려지고 있다. 이에 대한 연구가 전산모사 등으로 집중되고 있다. 또한 결정과 도가니의 회전 속도가 고액 계면의 형상에 영향을 미치는 것이 확인 되었다. 다결정의 경우에는 결정립계의 역할이 매우 중요하므로 이에 대한 연구가 진행되는데, 이들을 특히 전기적으로 비활성적인 쌍정 입계로 전환하는 연구가 진행되고 있다. 성장 조건을 변경시켜 쌍정 입계로 바꾸어서 재료의 전기적 성질을 향상시키는 결과를 확인하였다. 또한 성장 공정에서 발생될 수 있는 오염을 줄이기 위한 노력은 상부의 Ar 가스의 흐름을 상향 조절하여 불순물의 용입을 줄임이 확인되었다. 다음으로 mono-like인 경우에는 측면으로부터 성장 되어 들어오는 다결정이 단결정의 분율을 저하 시키는 주요 요인이 되고 있다. 이에 대한 해결책으로 하부의 냉각 속도를 높이고 상부와 측면에 단열재를 보강하는 방안이 제시되고 있고, 하부에 놓는 seed의 orientation을 조절하여 측면으로부터 성장 되어 들어오는 다결정을 억제하는 방안이 효과가 있음이 확인 되고 있다. Three kinds of crystalline silicon have been used for the solar cell grade. First of all, single crystalline silicon is the main subject to enhance the production yield. Most of the efforts are focused on the control of the melt-crystal interface shape affected by the crystal-crucible rotation rate. The main subject in the multi-crystalline silicon ingot is the contamination control. Faster Ar gas flow above the melt surface will lower the carbon contamination in the crystal. And also, twin boundary electrically inactive is found to be more effective than grain boundary for the improvement of the MCLT. In the case of mono-like silicon material, propagation of the multi-crystalline silicon growing from the inner side crucible is the problem lowering the portion of the single crystalline part at the center of the ingot. Crystal growing apparatus giving higher cooling rate at the bottom and lower cooling rate at the side crucible was suggested as the optimum solution obtaining higher quality of the mono-like silicon ingot. Proper application of the seeds at the bottom of the crucible would be one of the solutions.

최고경영자의 교체이유와 내부승진 및 외부영입 최고경영자의 이익조정 수준의 차이

이아영 ( A Young Lee ),전성빈 ( Sung Bin Chun ),박상수 ( Sang Su Park ),최종학 ( Jong Hag Choi ) 한국회계학회 2009 회계학연구 Vol.34 No.2

본 연구에서는 기업의 최고경영자 교체시에 외부영입한 경우와 내부에서 승진한 경우에 이익조정 정도에 차이가 있는지를 분석하였다. 또한 이러한 영입경로(외부영입 또는 내부승진)에 따른 이익조정 정도의 차이가 경영자 교체사유에 의해 달라지는지를 살펴보았다. 본 연구에 사용된 표본은 2001년부터 2005년 사이 최고경영자의 교체가 이루어진 총 239개의 기업-연도 표본이다. 실증분석에서 이익조정의 대용변수로는 경영성과를 통제하여 계산한 성과대응 재량적 발생액을 사용하였다. 실증적 분석의 결과는 다음과 같다. 우선 재량적 발생액의 절대값을 이용한 분석결과 외부영입한 경영자가 경영자 교체연도에 이익조정을 더 많이 수행한다는 것이 발견되었다. 이익조정의 방향성을 고려한 추가분석에 따르면, 외부영입과 내부승진 경영자 사이에 이익을 늘리는 방향인 양(+)의 이익조정 수준에는 유의적인 차이가 존재하지 않았으나, 이익을 줄이는 방향인 음(-)의 이익조정 수준에는 차이가 있었다. 즉 외부영입한 경영자가 더욱 적극적으로 음(-)의 이익조정을 실시한다는 발견이다. 그러나 경영자 교체 직전연도나 교체 직후연도에는 양 집단 간에 유의적인 차이가 전혀 발생하지 않았다. 이는 외부에서 영입한 경영자가 취임할 경우, 상대적으로 미래 기간의 이익을 높이기 위하여 현재의 이익을 낮추는 이익조정을 실시하여 취임연도에 저조한 경영성과를 보고할 가능성이 높다는 것을 나타낸다. 이에 반해 내부승진한 경영자는 전임 경영자와의 긴밀한 유대관계 때문에 이익을 낮추는 이익조정을 적극적으로 실시한 결과 과장되어 나타난 부진한 경영성과를 전임 경영자의 잘못 때문이라고 책임을 전가시키기가 힘들다고 할 수 있다. 추가적으로 경영자의 교체이유를 살펴본 결과, 경영자가 비정상적으로 교체되었을 경우 그리고 전연도의 경영성과가 부진했을 경우 더욱 더 이러한 추세가 뚜렷하게 나타났다. 이는 전임 경영자가 부진한 업적 때문에 문책성 교체를 당했을 가능성이 높은 표본들의 경우 외부영입 된 신임경영자가 이익을 낮추는 이익조정을 교체연도에 적극적으로 실시한다는 것을 의미한다. This study examines the association between the Chief Executive Officer (CEO, management) changes and the magnitude of earnings management of the firm. Especially, we examine if the types of management changes (either internal CEO promotion or external CEO recruitment) influence the magnitude of the earnings management. We define internally promoted new CEO as an internal management change and externally recruited new CEO as an external management change. In addition, we examine if the observed reason for the CEO changes is associated with the magnitude of the earnings management. Although there have been voluminous prior studies which investigate the magnitude of earnings management at the time of CEO changes, only the study of Strong and Myers (1987) and Lee et al. (2007) investigated this issue. However, they fail to find any consistent and significant association between the two, possibly due to several methodological limitations. This study revisits this issue after correcting those methodological problems. In addition, this study extends the scope of the research to the reason for the CEO changes: whether the reasons for the CEO changes are associated with the magnitude of earnings management by new CEO. On the one hand, it is possible that externally recruited CEO is more likely to take a big bath or manage earning downward at the year of appointment in order to lower the reported earnings. It is because he could blame inappropriate management of previous CEO for the poor performance of the year more easily. In contrast, internally promoted CEO may have difficulty in taking a big bath or managing earnings downward because he or she knows the former CEO well and has maintained close relationship with the former CEO. Thus, it may be difficult for the new CEO to blame the former CEO for the poor firm performance caused by the big bath or downward earnings management. With 239 CEO changes data collected over 2001-2005 periods from Korean listed companies, we empirically examine these predictions. The samples used in our analyses are taken from the study of Lee et al. (2007) but we remove 11 observations from their samples judged as outliers. Our sample is composed of all non-financial industry firms listed in Korean Stock Exchange. We use performance-matched discretionary accruals developed by Kothari et al. (2005) in order to proxy for the level of earnings management. During the sample selection process, we delete samples that the absolute value of the discretionary accruals is greater than 0.5 as outliers. Prior study of Ball and Shivakumar (2008) reports that it is very important to remove the effect of outliers in the research that uses the measure of discretionary accruals. Ball and Shivakumar (2008) suggest that Teoh et al.`s (1998) study fails to control outliers and their results do not hold when Ball and Shivakumar (2008) remove a few outliers from the analyses. The empirical findings are summarized as follows: First, using the full sample, we document that earnings management is more likely to occur at the time of management changes (both internal and external management changes). This finding is consistent with that in prior research of Lee et al. (2007) which use Korean data, and Murphy and Zimmerman (1993) and Pourciau (1993) which use the data of U.S. Second, using the full sample, we document a significant positive association between the level of earnings management and external management changes, compared with internal management change. Third, we separate the full sample into two groups of sub-samples based on the direction (upward (i. e., income-increasing) or downward (i.e., income decreasing)) of earnings management. When we use the sub-sample which adopts income-increasing discretionary accruals, we do not find any significant differences between the samples having external and internal management changes. However, when we use sub-sample which adopts income-decreasing discretionary accruals, we find that firms with external CEO changes are more likely to engage in income-decreasing earnings management, confirming the prediction that externally recruited CEO is more likely to deflate earnings in order to take a big bath or manage earnings downward. Further tests reveal that these findings are mostly due to the cases when the CEO changes occur in abnormal situation, for example, when poor financial performance of firms might cause the CEO change or when former CEO does not hold any position such as advisors or honorary president within the firm at all. In these cases, it is more likely that former CEO is replaced due to poor firm performance, not due to promotion or happy retirement. Similar to our study in part, Lee et al. (2007) investigate if there is any significant difference in terms of the magnitude of earnings management between internally promoted and externally recruited CEOs. They fail to find any significant association between the two, which is different from this study. We investigate what causes the differences and find out that they fail to correct or remove a few outliers in the discretionary accruals measure. When we judge outliers by using various criteria, our results are robust that externally recruited CEOs tend to manage earnings more. Our results which are different from those in Lee et al. (2007) suggest the importance of the need to control for the influence of outliers in discretionary accrual estimation processes. Our results suggest the importance of outlier controls in empirical analyses using ratio variables generated from complicated estimation procedures. This finding provides valuable insights to regulators, academics, firms, employees as well as many related parties into the behavior of new CEOs with respect to their motivation to manage earnings.

한국인 하악전돌증환자의 유전적 영향과 유전율에 대한 분석

김영호(Young Ho Kim),조한영(Han Young Cho),백채환(Chae Hwan Baek),이아영(Ah-Young Lee),김군종(Gunjong Kim),김휘영(Whi Young Kim),서영주(Young Ju Suh),백승학(Seung-Hak Baek),홍종락(Jongrak Hong),팽준영(Jun-Young Paeng) 대한구강악안면외과학회 2010 대한구강악안면외과학회지 Vol.36 No.6

Introduction: This study examined the genetic influence of mandibular prognathism epidemiologically in Korean families. Materials and Methods: Over a 5-year period from 2005 to 2009, a questionnaire with a pedigree chart was given to 100 (male 51, female 49) probands with skeletal Class III mandibular prognathism, who had undergone orthognathic surgery in Samsung Medical Center. Results: The average age of the probands was 22.1. The average SNA, SNB and ANB angles of the probands were 81.2􀆆, 84.1􀆆and -2.9􀆆, respectively. A total of 2729 (male 1,354, female 1,375) family members were examined, and the affected ratio of the families was 3.5% with no significant difference between genders. 45% of families had at least one member with a Class III malocclusion other than the proband. The affected ratio of the first-degree relatives (10.9%) was significantly higher than those of the second-degree (3.3%) and third-degree (1.9%) relatives. The affected ratio of the total relatives from the male probands (4.2%) was significantly higher than that of the female probands (2.8%). Heritability (h2, Falconer’method) was estimated to be 29.8% (0.298±0.059) in first-degree relatives. Conclusion: These results showed the significant influence of mandibular prognathism with relatively low heritability in first-degree relatives in Korean families of probands, who had undergone orthognathic surgery to correct a skeletal Class III malocclusion.

구두논문 : 단발성광고와 시리즈광고의 소구 방법에 따른 누적 효과에 관한 차이분석

이아영 ( Ah Young Lee ),이기복 ( Ki Bok Lee ) 한국감성과학회 2009 추계학술대회 Vol.2009 No.-

광고에서 가장 중요한 크레이티브 창출을 위한 광고 전략에 따른 시리즈 광고에서의 빈도별 축적에 의한 것이 어떠한 경우에 수요자들이 선호하느냐에 대한 따른 전략이 필요할때이다. 또한 소구방식에 따른 광고의 단발적 광고와 시리즈 광고마다의 메시지의 이해도나 구매 의욕도가 높아지는가를 측정하여 일회성의 광고와 연속적인 광고에서의 효과 적성을 각각 분류하여 연구한 이 논문은 광고의 제작을 함에 있어서의 더욱 효과적인 개선안을 참아 광고 효과를 높이는데에 이 논문의 연구목적을 둔다.

신남방정책 추진에 따른 부산 신항 효율성 제고에 관한 연구

이아영 ( Ah-young Lee ),김동진 ( Dong-jin Kim ) 한국생산성학회 2020 生産性論集 Vol.34 No.1

This research aims to analyze the small-medium size port competitiveness in the ASEAN-SAARC such as port of Leam Chabang in Thailand, port of Klang in Malaysia, port of Manila in Philippines, port of Ho Chi Minh City in Vietnam, port of Tanjung Priok in Indonesia, port of Colombo in Sri Lanka and port of Jawaharlal Nehru in India for establishing investment direction of Korea. ASEAN-SAARC is significant place in that it can be an economic diversification region to overcome Korea’s export-dependent economic structure and an alternative to addressing political and security factors not only the hegemonic war between China and the U.S but also the trade war between Korea and Japan. This study is established by Entropy and TOPSIS for the evaluation of port competitiveness based on the six main factors such as port facility, port location, port productivity, port cost, port service and socioeconomic stability. The result showed that no. of sail to Busan new port is ranked the most important factor with 0.14230, the revenue of import and export is the second with 0.11870 and the third with 0.11624 is unloading fee. While the berth productivity with 0.00620 was the worst valueless factor, terminal area is the 16th with 0.01103 and the volume of container with 0.02331 is ranked the 15th. In TOPSIS analysis, port of Klang was ranked top port with 0.67979 while port of Manila with 0.16119 was the worst competitive port comparing with other ports in the ASEAN-SAARC. This study suggests that port of Ho Chi Minh City is the most valuable port for Korea's investment among ASEAN-SAARC ports because not only it has a comparative advantage in port location, port productivity, port cost and port service but also Vietnam is most important country with trade of Korea. Therefore Korea should consider the investment to the port of Ho Chi Mich City for the purpose of improving productivity in Busan new port and connectivity with Vietnam through expanding port facilities such as depth extension and unloading equipment.

설계과정에서 나타나는 생태적 패러다임 실현의 한계

李娥榮(Lee Ah-Young) 대한건축학회 2006 建築 Vol.50 No.3

경영권방어수단의 존재가 자기자본비용에 미치는 영향

이아영(A Young Lee),강윤식(Yun Sik Kang) 한국관리회계학회 2021 관리회계연구 Vol.21 No.3

[연구목적] 본 연구는 경영권방어수단이 기업들의 자금조달비용에 어떠한 영향을 미치는지 자기자본비용을 이용해 살펴보고자 한다. 이를 통해 경영권방어수단과 관련된 상반된 가설인 경영자참호구축가설과 이해일치가설을 검증한다. [연구방법] 본 연구는 2011년부터 2018년까지 유가증권 시장에 상장된 기업을 대상으로 경영권방어수단의 존재가 자기자본비용에 미치는 영향을 분석하였다. 자기자본비용은 자본자산가격결정모형(CAPM)을 이용하여 추정하였으며, 내재자본비용을 이용한 추가분석도 제시하였다. [연구결과] CAPM에 근거하여 자기자본비용을 추정한 결과에서 경영권방어수단이 있는 기업의 자기자본비용이 경영권방어수단이 없는 기업에 비해 높은 것으로 나타났다. 이것은 경영권방어수단의 존재로 주주권이 약화된 경우 사적이익을 추구하는 지배주주의 과도한 투자로 기업변동성이 증가되고 결국 높은 위험프리미엄을 초래한다는 해석을 가능하게 한다. 한편 내재자본비용을 자기자본비용의 대용치로 사용한 분석에서는 경영권방어수단과 자기자본비용 간의 유의미한 관계를 발견할 수 없었다. [연구의 시사점] 본 연구는 한국자료를 이용하여 경영권방어수단과 자기자본비용 간의 관계를 살펴보았다는 점에서 의미가 있으며, 자기자본비용에 영향을 미칠 수 있는 변수로 경영권방어수단 변수를 발견했다는 점에서 중요한 시사점이 있다. [Purpose] This study examines how anti-takeover provision(ATP) affects the financing cost of companies using equity capital costs. Through this, entrenchment hypothesis and alignment hypothesis, which are conflicting hypotheses related to anti-takeover provision, are verified. [Methodology] This study uses companies listed on the securities market from 2011 to 2018. The cost of equity capital was estimated using the Capital Asset Price Determination Model (CAPM), and the results of using the intrinsic cost of equity capital are also reported in further analysis. [Findings] As a result of empirical analysis, it was found that the cost of equity capital of companies with anti-takeover provision was higher than that of companies without antitakeover provision. This means that if shareholder rights are weakened due to the presence of anti-takeover provision, the controlling shareholder will make excessive investments in the process of pursuing private interests and increase corporate volatility, increasing risk premiums. On the other hand, in the analysis using intrinsic capital cost as a substitute for equity capital cost, no significant relationship could be found between anti-takeover provision and equity capital cost. [Implications] This study has implications in that it examines the relationship between anti-takeover provision and cost of equity capital using Korean data, and has a contribution in that it discovered anti-takeover provision as variables that can affect cost of equity capital.

농장 기반 가족단위 치유농업 프로그램 운영 및 효과 검증

이아영(A-Young Lee),김선옥(Seon-Ok Kim),박신애(Sin-Ae Park),이왕록(Wang-Lok Lee),김대식(Dae-Sik Kim) 한국원예학회 2018 한국원예학회 학술발표요지 Vol.2018 No.10