외국인직접투자기업의 성장요인에 대한 실증분석 : 기업규모 및 나이를 중심으로

성효용 한국산업조직학회 2003 産業組織硏究 Vol.11 No.2

본 연구는 Gibrat 법칙의 검증을 통해 한국에 진출한 외국인 직접투자 foreign direct investment 기업의 성장과 규모간의 관계를 분석하였다. 첫째, 외국인직접투자기업이 일반적인 Gibrat 법칙의 가정을 충족시키는가를 검증하였고, 둘째, 외국인직접투자기업에 있어서 규모와 성장간의 관계가 내국인 소유 제조업체의 경우와 어느 정도 다른가를 비교분석 하였다. 분석결과에 따르면 한국제조업 전체를 대상으로 한 경우와 외국인직접투자기업 및 내국인 소유 제조업체의 경우 모두 기업성장들과 기업규모간에 통계적으로 유의미한 상관관계가 나타나 Gibrat법칙이 기각되었다. 반면 기업나이와 기업성장간에는 통계적으로 유의미한 음의 상관관계를 보임으로써 Jovanovic의 기업성장이론을 지지하는 것으로 나타났다. This study analyzes the relationship between firm growth and factors such as firm size and age of Foreign Direct Investment firms in Korea. It includes the impact of ownership and chaebol on firm growth. The estimation results show that in general, smaller and younger firms grow faster than larger or older firms, for both FDI and domestic firms, rejecting Gibrat's theory of firm growth, but supporting Jovanovic's learning model of firm growth. Nevertheless, foreign ownership had a positive impact on firm growth in general, showing that they have asset specific advantages other than firm size which help them to grow.

실험적 치아이동에 의한 백서 치주인대내 CGRP 면역 양성 신경섬유의 변화

성정옥,박효상,배용철,성재현 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.5

교정력에 의하여 치주인대내에 생긴 압박측에서는 국소적 염증반응과 골 흡수가 활발히 일어나며 신장측은 골 생성이 활발하므로 뒤 두 부위는 서로 다른 조직반응이 일어난다. 치아이동에 관여하는 것으로 알려진 CGRP 면역 양성 신경섬유도 압박 및 신장 부위에 따라 다를 것으로 생각된다. 저자등은 CGRP 면역 양성 신경섬유의 교정력 적용시간에 따른 변화를 관찰하고 압박 및 신장력을 받는 부위에 따른 변화를 관찰하기 위하여 200gm 내외의 생후 9주령 백서 상악 제1 대구치에 Ni-Ti coil spring으로 80gm내외의 교정력을 12시간, 1일, 3일, 7일, 12일동안 가한 후 희생하여 면역 조직화학법으로 염색하여 관찰하였다. · 교정력 적용 12시간 및 1일군에서 압박 및 신장측 모두에서 CGRP 면역 양성 신경섬유가 감소되었다. · 교정력 적용 3일군에서 CGRP 면역 양성 신경섬유는 많은 가는 분지가 관찰되며 증가되었고 특히 신장측에서 현저하였다. · 교정력 적용 7일군에서 비교적 굵은 CGRP 면역 양성 신경섬유도 증가 되었으며 신장측에서 현저하였다. · 교정력 적용 12일군에서 압박측 치주인대에서는 거의 정상과 유사하였으나 신장측치주인대에서는 증가된 채 유지되었다. · CGRP 면역 양성 신경섬유는 압박측보다 신장측에서 더 많이 증가하여 치아이동시 CGRP가 말초조직에서 염증반응에 관여함과 동시에 골 개조에도 상당한 연관성을 가지고 있을 것으로 생각된다. Bone resorption was predominate in compression site, bone formation in tension site of periodontal ligament during tooth movement. The biologic response at compression site was different from tension site. Thus the CGRP immuno-positive nerve fiber will respond differently to mechanical force according to the area(compression or tension site). The purpose of this study was to investigate this response of CGRP immuno-positive nerve fiber in the periodontal ligament according to the duration of applied force and the area (compression or tension site) during experimental tooth movement. The experimental animals were 7 week old male rat (approximately 200 gm). The orthodontic force was applied mesially to the right maxillary molar using the Ni-Ti coil spring during 12hours, 1, 3, 7, and 12days. Immunohistochemical staining using antibody against CGRP was performed after sacrifice. The results were as follows. The CGRP immuno-positive nerve bundle showed reduced immunoreactivity and nerve fibers reduced in density after application of orthodontic force for 12 hours and 1day. The CGRP immuno-positive nerve fibers showed many thin branches at the apical periodontal ligament after application of force for 3 days as compared with normal. The tension site in the apical periodontal ligament showed more branches than the compression site. In 7 day group, the CGRP immuno-positive nerve fibers increased in terms of the number and had many thin branches in the apical periodontal ligament. The tension site had more branches than the compression site. In 12 day group, the CGRP immuno-positive nerve fibers showed similar distribution to normal control at compression site of apical periodontal ligament, but the fibers at the tension site increased in number. The CGRP immuno-positive nerve fibers showed more increased at tension site than compression site after application of orthodontic force. Therefore it seems to have some relation to the bone remodeling besides the local inflammatory process.

합리적 선택을 위한 경제교육

성효용 한국경제교육학회 2003 경제교육연구 Vol.10 No.1

1997년 말 발생한 IMF 경제위기 이후 경제에 대한 관심도는 급격히 높아졌다. 특히 최근에 늘어나는 신용불량자에 대한 사회경제적 문제로 인해 어린시절부터 경제교육이 시작되어야 한다는 주장과 함께 초 ? 중 ? 고등학교 및 대학교의 경제 ? 경제학교육에 대한 내용 및 교수방법에 대한 논의가 활발히 대두되고 있다. 또한 청년실업으로부터 발생하는 사회적 문제에 효과적으로 대처하기 위해서는 경제교육을 강화해야 한다는 의견이 정부 및 관련 교육자들로부터 제기되고 있다. 현실에 대한 경제적 이해와 건전한 소비생활을 유도하기 위해서는 장기적으로 가정과 학교에서 어린이를 대상으로 하는 경제교육 프로그램이 개발되고 시행되어야 한다. 이와 같은 경제교육은 우리나라의 금융시장을 건전하게 발전시키기 위한 중요한 요소라고 할 수 있다. 따라서 경제교육 프로그램을 개발하여 지속적으로 학교에 보급하고, 교육과정을 통해 올바른 경제인을 양성하는 노력이 요구된다고 하겠다. Since the financial crisis in 1997, interests and concerns about the economy have been rapidly increased. Especially, due to a social problem about the recently increased number of people with bad credit, with the argument that economic education should be started from childhood, the contents and teaching methods for economic education of elementary, middle and high school, and college have been actively discussed. In order to cope with important social problems like unemployment among youth, the government and related educators suggest to strengthen economic education. To induce economic understanding in reality and to educate healthy consumers, economic programs should be developed and performed for children at their home and school in the long-term. Economic education for children can be an important factor to skillfully function at the financial market. Therefore, it is required to develop economic programs and then continuously spread them to schools and demand for efforts to train well educated economic persons through the education curriculum.

Study on Microstructure and Mechanical Properties of the Al–25Cr–5Si (at%) Alloy Powder Using Gas-Atomization and SPS Process

Yong‑Ho Kim,Hyo‑Sang Yoo,Jeong‑Han Lee,Ik‑Hyun Oh,Hyun‑Kuk Park,Hyeon‑Taek Son 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

In order to investigate the microstructure and mechanical properties on Al–25Cr–5Si (at%) alloy, a mixed powder with pureelements and an alloy powder using a gas atomization process were used. Fine and high purity Al–25Cr–5Si (at%) alloypowder was successfully prepared by gas atomization and densified using a spark plasma sintering (SPS) process. The overallpowder size distribution of the mixed Al, Cr, and Si elemental powders was in the range of 10–15 μm. The atomized Al–Cr–Sialloy powder was fine and spherical in morphology and difficult to be formed by intermetallic formation. Densification wasclearly confirmed at 1000 °C, with almost isolated pores formed, by clear removal of pores between particles, deformationof particles, an increase in the number of contacts, and a change in size between particles. As a result of XRD analysis ofthe sintered compacts, single phase was observed using the mixed powder, but the compact using gas atomization remainedthe alloy phase even at the process temperature. The Vickers hardness of the compacts by mixed powder was observed at59.70 Hv and the compact using gas atomized powders on the temperature 1000 °C of the Vickers hardness increased to702.6 Hv. The compressive yield strength of the compact with mixed powder was 195.24 MPa and the compressive strengthof the compact with gas atomized powder increased to 802.07 MPa. It is considered not to be decomposed by the AlCrSi,Al13Cr4Si4and Al8Cr5phases sintering process, resulting from the improvement of mechanical properties.

加味金櫃腎氣丸의 抗癌 및 抗轉移 效果에 關한 硏究

김용태,전영수,김정효,김성훈 대한한방종양학회 1999 대한한방종양학회지 Vol.5 No.1

To evaluate the antitumor activity and antimetastatic effats of Kamigumgusingihwan(KGSH) studies have ken dom. The results were obtained as follows: 1. KGSH extras exhibited a weak cytotoxicity against A549, SK-OV-3, B16-F10, and SK-MEL-2 cell lines. But exhibited potent cytotoxicity against P388 cell line in a dose-dpendent manner. 2. The concentration inhibiting adhesion of A549 to complex extracellular maMx up to below 30% of control was recognized at 10^-3g/ml of KGSH 3. KGSH extrats showed a wed inhibitoty effect on DNA topo- isomerase I from calf thyus. 4. The T/C% wa 137% in KGSH treated group in S-180 bearing ICR mice. 5. In pulmonary colonization assay. a number of colonies in the lungs were decreased sigruncanny in KGSH treated group as compared with control group. 6. In hematological changes in Bl6-BL6 injected C57BL/6, numbers of WBC were decreased insignificantly in KGSH treated groups, and also those of platelet were inoeased insignificantly in KGSH treated groups as compared with control. 7. In CAM asay, KGSH extracts inhibited angiogenesis at 15ug/egg concentration significantly as compared with control. Taken together these results, it is strongly demonstrated that KGSH significantly suppressed tumor metastasis by blpcking cell adheion to exuaalula matrix. Therefore. KGSH is expected to be clinically a potem antimetastatic drug for the prevention and treatment of cancer.

집토끼 동방결절의 활동전압에 미치는 Vanadate의 효과

조용문,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.3

In order to investigate the electrphysiological effect of vanadate, a potent inhibitor of Na^+-K^+ pump, on the cardiac muscle, the alteration of transmembrane potential as influenced by the drug was measured in rabbit SA rodes in vitro by means of KCI glass intracellular microelectrodes. The followings were results of findings: 1. The rate of spontaneous firing was decreased in the presence of vanadate and the maximum inhibition which was about 50% of contral level was obtained at drug concentrations of 10^-3 M or higher. 2. The maximum diastolic potential(M.D.P.) was depressed by vanadate in a dose-dependent manner and the maximum inhibitory effect was obtained at the drug concentration of 10^-3 M. However the peripheral pacemaker cells were more resistant to the drug effect than the central pacemaker cells at lower concentrations of the drug. 3. In both central and perepheral pacemaker cells, vanadate had no effect on the M.D.P. in concentrations up to 5×10^-4 M. However on at 5×10^-2 M, the drug depressed the M.D.P. in the peripheral cells. 4. Changes of the action potential induced by vanadate were qualitatively similar to those occuring when the calcium concentration of the bathing medium was raised to 4mM. These results may be interpreted as that vanadate increases the rate of Ca^++ influx info the cell in S-A nodes.

집토끼 동방결절부위별 자동능에 대한 CA^(2+)의 효과

방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1985 中央醫大誌 Vol.10 No.1

Effects of external Ca^2+ on the spontaneous firing rates of the isolated rabbit atria, the whole SA node, and the small strips of SA node at constant temperature were observed and analyzed by recording the transmembrane action potentials. The results were as follows: 1. It has been shown that a positive chronotropic effect in the isolated atrium and whole SA node has appeared at elevated Ca^2+ concentration. 2. On the contrary, negative chronotropic effect of Ca^2+ were observed in a small strip of SA node. 3. The each small strip of SA node could be divided into two kinds of cells, i.e., peripheral pacemaker cells and central pacemaker cells. In central pacemaker cells, Ca^2+ has shown positive chronotropy but opposite effect was observed in peripheral pacemaker cells. 4. The central pacemaker cells of the small strip of SA node could be divided into two groups with. configuration and parameters of action potentials. The two groups showed different degree of positive chronotropic effect respectively with elevated Ca^2+ concentration.

위 평활근 세포의 활동전압을 이루는 CI^-전류성분에 관한 연구

방효원,이종찬,이무열,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1993 中央醫大誌 Vol.18 No.3

Chloride current has been known as a part of backgroud current. Recently, its roles in the maintenance of action potential have much attention. The purposes of the present study are clarifying the chloride current component which might play an important role in generation and maintenance of the action potential in the pyloric circular smooth musele cells. We used the whold cell voltage clamp techniques to assess the current and voltage responses induced by caffeine superfusion. The results were as follow: 1. Caffeine superfusion induced the increase of inward currents in the hyperpolarized potential ranges, and the increase of outward currents in the depolarized ranges. 2. Sodium ion removal from the external medium and the addition of cadmium ion rarely affected these current response. 3. Duration of the action potential was elongated by application of the caffeine and modified by the change of the intracellular chloride ion concentraion. 4. The effect of caffeine superfusion on the action potential disappeared by the addition of the anion channel blocker. The results suggest that caffeine superfusion may prolong the duration of repolarized phase of the action potential probably by the chloride current activation in the gastric antral smooth muscle.

여성 요도증후군에서 Terazocin의 효과에 대한 연구

우승효,신관희,한광희,정원일,이형래,이상철,김용태,김원재 충북대학교 의학연구소 2000 忠北醫大學術誌 Vol.10 No.2

연구목적: 여성 요도증후군을 보이는 환자에서 교감신경차단제인 terazocin을 복용한 후 치료 효과에 대한 각 증상의 변화와 부작용을 알아보고자 하였다. 대상 및 방법: 1997년부터 1999년까지 충북대학교병원 비뇨기과에 내원한 35명의 여성 중 요검사 및 요배양 검사, 그리고 다른 이학적 검사에서 이상이 없는 요도증후군 환자를 대상으로 간질성방광염 증상점수(ICSS)를 terazocin (3mg/day for 3 months) 투여 전후에 조사하였고, 치료 후 3개월과 1년에 Likert scale 점수를 조사하였다. 결과: ICSS는 비치료군은 18.3±5.9점, 치료군은 16.5±6.8점으로 두군간의 차이는 없는 것으로 나타났다(p=0.52). 치료군은 치료 후 3개월에 시행한 ICSS가 9.9±7.8점으로 치료 전에 비해 현격히 증상이 호전되는 것으로 나타났다(p=0.0001). 특히 3개월에 시행한 Likert scale에서는 주간 및 야간빈뇨, 절박뇨, 배뇨통의 횟수 및 강도, 그리고 전체적인 증상정도에서 40-70% 가량 호전된 것으로 밝혀졌으며 이는 1년 후에도 증상의 호전이 지속되는 것으로 나타났다. 비치료군에서의 1년 후 Likert scale은 6명 중 2명이 전체적인 증상의 호전이 있는 것으로 나타났다. 결론: Terazocin은 환자의 약 70%가량에서 증상의 호전을 가져왔고, 비치료군에서도 환자의 33%가 저절로 증상이 좋아진 것으로 보아 Terazocin은 여성 요도증후군에서 분명히 효과가 있으나 증상이 심할 경우 보조적인 치료로 이용되는 것이 바람직할 것으로 사료된다. Purpose: We performed to assess the effects and complications of terazocin in women with chronic female urethral syndrome. Materials and Methods : Thirty-five women with chronic female urethral syndrome were studied from March 1997 to August 1999. The subjects exhibited normal findings without the pyuria and bacteriuria in urinalysis and urine culture and were invested the interstitial symptom score(ICSS). 29 subjects of them took a terazocin 1-4 mg/day for 3 months. They were reevaluated for the ICSS and Likert scale after 3 months and for Likert scale after 1 year. Results: The ICSS before treatment were showed 18.3±5.9 in the untreated patient group and 16.5±6.8 in the treated patient group, and no statistically difference between both patient groups(p=0.52). In the treated patient group, the ICSS after treatment were showed 9.9±7.8, significant difference between before and after treatment(p=0.0001). The Likert scale was showed at 3 months after treatment that frequency, nocturia, urgency, pain frequency, pain intensity, daily activities, and overall symptoms were improved in 65.5%, 55.2%, 24.1%, 41.4%, 41.4%, 70%, 70%, and 70% of 29 subjects, each other. Overall symptom score assessed at 1 year were showed that 3 subjects was aggravated. In untreated patient group, 2 of 6 was improved in overall symptom score. Conclusion: Terazocin was effective above 70% in the treated group, and symptoms were improved spontaneously in a third of the untreated group. So, we thought that terazocin would be useful as supportive treatment in period of severe symptoms.

Polyacrylate 수화겔의 약물방출특성에 관한 연구

차효복,이성길,이용택 慶熙大學校 材料科學技術硏究所 1998 材料科學技術硏究論集 Vol.11 No.-

SAc hydrogels were prepared by crosslinking of concentrated aqueous solutions of poly(acrylamide)(PAm) and poly(sodium-acrylate)(PSAc) in N_(2) gas. The equilibrium swelling studies of SAc hydrogels were carried out in solution of varing pH. The gel was swollen extensively in the solution of pH 6 when compared to that of pH 2. Riboflavin and L-ascorbic acid was loaded and the in vitro release studies were carried out in pH solution. The results of this study suggest that drug release is proportion to swelling ratio. SAc hydrogel with drug is corresponded to the soluble matrix pharmaceutical preparation.