벤처기업의 유형구분과 경영성과

李章雨,李玹淑 한국중소기업학회 2000 기업가정신과 벤처연구 Vol.3 No.2

The purpose of this study is to derive the taxonomy of high-tech venture in Korea, and identify the relationships of types and performance. A Taxonomy of high-tech ventures are examined by cluster analysis using the date generated from questionnaire response from 116 entrepreneurs. As a result, a taxonomy describes four types of venture business in Korea. These types are profiled across five dimensions : entrepreneurs, strategy, structure, environment, resource and capability. A taxonomy is an ideal type generated by cluster analysis. It is a composite summary of the case descriptions of the venture that fell into each particular cluster. Although each venture taxonomy is a complex combination of many different characteristics. It is outlined to provide an overall view of the taxonomy in Korea.

茵蔯淸肝湯이 肝保護 및 纖維化 抑制에 미치는 影響

승현석,김영철,이장훈,우홍정 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2003 東西醫學硏究所 論文集 Vol.2003 No.-

Objective : The aim of this study is to investigate the inhibitory effect of Injinchunggantang on hepatic sclerosis induced by CCl₄. Methods : Weight, liver function test and complete blood cell count, gross findings, and findings on liver tissue of the past(Hematoxylin & Eosin stain, Masson-Trichrome stain) were studied. Results : When it comes to the change of rats body weight, The CCI₄-Injinchunggantang group lost far less weight than The CCl₄ only group. In the liver function test, which is focused on various area such as total cholesterol, alkaline phosphotase albumin, aspartate transaminase, alanine transaminase, The CCl₄ Injinchunggantang group was much more closer to normal limit than the CCl₄ only group. In the complete blood cell count, including while blood cell, red blood cell, hemoglobin, hematocrite, platelet, The CCl₄ Injinchunggantang group significantly closer to normal limit than CCl₄ only group. In the gross findings of hepatic fibrosis models, Injinchunggantang showed inhibitory effect on hepatic fibrosis in the order. In the past findings of hepatic fibrosis models in Hematoxylin & Eosin, Masson-Trichrome staining, the liver in CCl₄ only group showed atrophy and necrotic change with white nodules, whereas that of CCl₄ Injuchuinggantang group showed lesser significant change with the well preserved tone of the tissue. In the extent of the inhibition of the hepatic fibrosis, the Injinchunggantang group showed statistically significant inhibitory effect(p<0.05) in the sclerosis model. Conclusions : These results show that Injinchunggantang have inhibitory effect on hepatic sclerosis induced by CCl₄ and further ultimately prevent liver cirrhosis. To obtain more credible results in the experiment, the invention of a new experimental model more similar to human hepatic sclerosis is still needed.

약 내향 비확대 다가사상의 고정점 정리

배종숙;안대종;장우성 명지대학교 자연과학연구소 2004 자연과학논문집 Vol.23 No.-

In this paper, we prove fixed point theorems for weakly inward multivalued nonexpansive maps on a Banach space satisfying Opial condition. 이 논문에서 우리는 Banach 공간에서 Opial 조건을 만족하는 약 내향 비확대 다가사상의 몇 가지 고정점정리를 증명하였다.

손상평가도를 이용한 용접구조물의 균열형 결함에 대한 사용적합성 평가

李精錫,朱章福,張宰溢,金禹植,고영대,權東一 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.10

Flaws nucleated during operation of structures such as nuclear power plants, petroleum facilities and gas equipment raise many safety problems, and thus the integrity assessment of crack-like flaws in structures has been very important. Since large-scale structures include weldments with complex micro-structures and inhomogeneous material properties, it is essential to consider both metallurgical and mechanical factors. In this study, a methodology for integrity assessment in welded structures was developed based on API 5L X65 grade natural gas pipeline (an approximately 2400 ㎞ pipeline in Korea). A failure assessment diagram(FAD), which includes all failure modes from linear elastic fracture to plastic collapse, was used for integrity and fitness-for-service(FFS) assessment of the pipeline. Since tensile properties and fracture toughness of base metal, weld metal and heat affected zone(HAZ) are required for the FAD, tensile tests and fracture toughness tests were performed on each region. In particular, the evaluation of representative properties of HAZ make it possible to assess FFS accurately by using the HAZ-based FAD when crack-like flaws exist in HAZ. This HAZ-based FAD is different from current codes, which assess integrity by the material properties of weld metal or base metal even when flaws exist in HAZ.

Pd 촉매하에서 allylic alcohol과 hypervalent iodine 화합물의 위치 선택적 vinylation에 관한 연구

강석구,이홍우,장수범,김태현,편성재 성균관대학교 기초과학연구소 1995 論文集 Vol.46 No.2

The formation of carbon-carbon bond by palladium-catalyzed coupling of aryl or vinyl halides with olefins, known as the Heck reaction, has become a powerful tool in organic chemistry. In the case of allylic alcohols, palladium-catalyzed reaction of organic halides usually affords β-substituted ketones or aldehydes rether than β-substituted allylic alcohols.

브라켓 재생시 표면 처리 방법에 따른 전단 접착 강도에 관한 연구

임장빈,이진우,차경석 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.5

본 연구는 현재 브라켓의 개발 양상이 tip, torque 등이 브라켓 내에 내재되어 있는 straight wire appliance의 도입으로, 브라켓의 디자인은 더욱 세밀하고, 복잡해져 점차 고가화 되어 재사용의 요구가 증가하는 점에 맞추어 계획되었다. 본 연구의 목적으로는 재생과정의 목표에 부합하는 브라켓 접착면의 재처리 방법을 찾는 것이다. 실험 방법은 금속 브라켓, 도재 브라켓 각 5개씩 5군으로 나누어 브라켓 기저부에 재처리과정을 시행한 후, 이를 치아에 접착하고 만능 시험기(universal testing machine)을 사용하여 치아에서 브라켓이 탈락하는 시점의 최대 전단접착강도를 채득하였으며, 그 후 치아의 법랑질 표면을 입체 현미경으로 관찰하여 파절면의 접착제 잔류지수를 구하였다. 또한 입체 현미경 (stereoscopic microscope)과 주사전자현미경 (SEM) 화상으로 재처리된 브라켓의 접착면을 관찰하였다. 이와 같은 실험으로 다음과 같은 결론을 얻었다. 1. 금속 브라켓에서 접착 강도가 가장 높은 재처리 방법은 sandblasting을 8초간 시행한 군이었으며, 이는 제조회사에서 제작된 원래 상태인 대조군의 접착강도보다도 오히려 높았다. 2. 세라믹 브라켓에서 접착 강도가 높은 재처리 방법은 8초간 sandblasting한 군이었으나, 대조군의 접착강도 보다는 낮았다. 3. Sandblasting 시간을 4초에서 8초로 증가시킨 경우 금속 브라켓의 접착강도는 급격히 증가하는데 비해 도재 브라켓의 접착강도는 별 차이가 없었다. 그 이유는 도재 브라켓의 경우 브라켓 접착부의 표면적 증가에도 불구하고, 금속 브라켓과는 달리 브라켓 자체의 물성 차이로 인해 도재 브라켓에서의 접착력을 좌우하는 거대 기계적 결합부위의 파손이 일어나 접착력의 약화를 가져왔기 때문이다. The purpose of this study is to find the optimal reconditioning method for a debonded bracket base. In this study, metal brackets and ceramic brackets are used. There are devided into five groups by reconditioning methods (A : control(new bracket). B : heat treated, C : grinded with green stone, D : sandblasting for four seconds, E : sandblasting for eight seconds). Each reconditioned brackets were bonded and shear bond strength was measured by universal testing machine. After debonding, enamel surfaces were examined under stereoscopic microscope to determine the adhesive remnant index. The Microstructure of reconditioned bracket were examined by SEM (JSM 5200, Japan) and stereoscopic microscope (SZ-ST, Japan). 1. In metal bracket groups, sandblasting for eight seconds revealed the greatest shear bonding strength and its strength was above that of control group. 2. In ceramic bracket groups, sandblasting for eight seconds revealed the greatest shear bonding strength but its strength was below that of control group. 3. As sandblasting time was increased, shear bonding strength of metal bracket was increased very much, but in ceramic brackets, shear bonding strength exhibited limited increase. This difference was caused by macro-mechanical retentive areas of ceramic brackets were broken for their brittle characteristics of material.

Pd 촉매 하에서 terminal alkynes, aryl, alkenyl 혹은 alkynyl iodine 화합물의 수용성 조건에서 cross-coupling에 관한 연구

강석구,이홍우,장수범,호필수 성균관대학교 기초과학연구소 1995 論文集 Vol.46 No.2

The ligand-free Pd(OAc)_2-catalyzed coupling reaction of aryl-, alkenyl-, and alkynyliodonium tetrafluoroborate and iodanes with terminal alkynes proceeds readily in the presence of NaHCO_3 in aqueous medium to afford the substituted alkynes in high yields under mild conditions.

CBD으로 제작한 In:Cd_(1-x)Zn_(x)S/CdTe 태양전지의 전기적 특성에 관한 연구

심재선,송우창,방영근,김남석,임창민,장현 三陟大學校 2006 論文集 Vol.39 No.-

CdS thin films have been widely used a window material in heterojunction solar cells. In solar cell systems, where CdS thin films have been proved to be useful, partial substitution of Zn for Cd increases the optical window of the hetero-junction and also the diffusion potential. In this thesis, effects of the thickness of indium films and the annealing temperature on structural, optical and electrical properties of chemically deposited CdZnS films for the efficiency of the Cd_(1-x)Zn_(x)S/CdTe solar cells were investigated. Cd_(1-x)Zn_(x)S films were grown by chemical bath deposition (CBD), which is a very attractive method for low-cost and large-area solar cells. The open circuit voltage of Cd_(1-x)Zn_(x)S/CdTe solar cells increased due to reduced electron affinity difference between Cd_(1-x)Zn_(x)S and CdTe films. However, the conversion efficiency of Cd_(1-x)Zn_(x)S/CdTe solar cell decreased because of the higher series resistance(R_(s)) than CdS/CdTe solar cell. The series resistance and conversion efficiency of Cd_(1-x)Zn_(x)S/CdTe solar cell were improved by using indium-doped Cd_(1-x)Zn_(x)S films as window layer. Cd_(1-x)Zn_(x)S/CdTe solar cells fabricated with optimal conditions exhibited V_(oc)=630mV, J_(sc)=38.89mA/㎠ , FF=0.53, and η=13.2%

저장기간에 따른 3개 수종의 종자 및 발아 특성 변화

한심희,김찬수,장석성,이현주,탁우식 한국농림기상학회 2004 한국농림기상학회지 Vol.6 No.3

This study was conducted to examine the changes in the seed physical characters and germinative properties of three tree species at three different storage times in order to determine the most suitable storage time and condition. Seed physical characters and germinative properties were examined from seeds of Fraxinus rhynchophylla, Zanthoxylum schinifolium and Staphylea bumalda that were stored at -18C for 1, 3 and 10 years, and the growth performance and physiological characters of their seedlings were analyzed. Seed physical characters and germinative properties showed significant differences between three storage times as well as three tree species. Seed moisture content of F. rhynchophylla and S. bumalda and seed fresh weight of Z. schinifolium decreased with increase of storage time. Storage time represented negative correlation with moisture content and fresh weight (r = -0.822, p < 0.01). Seed percent germination of Z. schinifolium and S. bumalda stored for 3 and 10 years decreased less than 15% and 10.7% respectively. Mean germination times for seed of F. rhynchophylla, Z. schinifolium and S. bumalda were delayed 11.9, 5.7 and 9.7 days after a storage time of 10 years, respectively. However the growth and viability of seedlings didn't show a special pattern for storage time and tree species.

양극성 장애와 Monocyte Chemoattractant Protein-1 유전자 다형성

배치운,김태석,장우영,김정진,이창욱,이수정,전태연,이철,백인호 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.5

Objectives : Several studies suggested that cytokines could be involved in the pathogenesis of mood disorders, while data for bipolar disorder is relatively deficient (BD). BD, Knowned to have a inherited tendency, has been considered to be related with T-helper cell system. This study was designed to investigate the association between polymorphism of monocyte chemoattractant protein-1 (MCP1) gene at promoter-2518 and BD. Methods : Patients with BD (n=92) in accordance with DSM-FV criteria and control subjects (n=114) participated in this study. DNA was extracted from whole blood and the MCP-1 gene promoter region was amplified by polymerase chain reaction-based method. Results : Genotype and allele distributions in patients with BD were not different from those of control subjects (p=0.587 ; p=0.384). Genotype and allele distributions in accordance to presence or absence of suicide attempt (p=0.423), family history (p=0.733) and psychotic feature (p=0.436) were not different between the two groups. Conclusion : Present study suggests that the MCP1 promoter -2518 polymorphism may not affect the susceptibility and clinical diversity of the development of BD.