• Safety and Health at Work
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• 제1권1호
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• pp.43-50
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• 2010

Objectives: The objective of this study was to investigate the effect of chain installation condition on stress distribution that could eventually cause disastrous failure from sudden deformation and geometric rupture. Methods: Fractographic method used for the failed chain indicates that over-stress was considered as the root cause of failure. 3D modeling and finite element analysis for the chain, used in a crane hook, were performed with a three-dimensional interactive application program, CATIA, commercial finite element analysis and computational fluid dynamic software, ANSYS. Results: The results showed that the state of stress was changed depending on the initial position of the chain that was installed in the hook. Especially, the magnitude of the stress was strongly affected by the bending forces, which are 2.5 times greater (under the simulation condition currently investigated) than that from the plain tensile load. Also, it was noted that the change of load state is strongly related to the failure of parts. The chain can hold an ultimate load of about 8 tons with only the tensile load acting on it. Conclusion: The conclusions of this research clearly showed that a reduction of the loss from similar incidents can be achieved when an operator properly handles the installation of the chain.

• 생약학회지
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• 제30권3호
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• pp.290-294
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• 1999

From the legumes of Albizzia julibrissin Durazzini (Leguminosae), a mixture of long-chain alcohols, ${\alpha}-spinasterol$, a mixture of acylated sterol glycosides and ${\alpha}-spinasteryl$ $3-O-{\beta}-D-glucoside$ were isolated. Two mixtures of long-chain alcohols and acylated sterol glycosides were characterized as 1-hexacosanol (major) and 1-tetracosanol, and $3-O-[6'-O-palmitoyl-{\beta}-D-glucosyl]-{\alpha}-spinasterol$ (major) and its 6'-O-stearoyl ester. All compounds were identified on the basis of spectral data and chemical reactions.

• 통상정보연구
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• 제1권1호
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• pp.11-32
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• 1999

최근 물류분야의 학자들과 실무자들이 물류혁신의 한 기법으로 자주 거론하는 공급사슬관리(Supply Chain Management: SCM)의 정확한 개념은 무엇인가? 기존의 여러 문헌과 물류실무를 검토한 결과 특정한 공급사슬내의 조직내부 또는 조직간에는 일정한 수준의 경영활동 및 업무절차의 조정의 필요한 것으로 인식되고 있다. 본 연구에서는 향후 공급사슬관리와 관련된 의사결정에 도움을 줄 수 있는 개념적 모델을 제시하고, 이를 토대로 한국기업의 물류혁신을 위한 시사정과 앞으로의 연구과제에 대해 알아보고 있다.

• 한국진공학회지
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• 제15권1호
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• pp.31-36
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• 2006

[ $Li/Ge(111)-3{\times}1$ ] 표면의 구조를 고찰하기 위해, Ge 3d core-level 광전자 스펙트럼을 분석하였다. Curve fitting을 통하여 스펙트럼에서 bulk Ge 3d peak에 해당하는 peak의 양쪽에 각각 하나씩의 표면 성분이 있음을 확인하였다. $Li/Ge(111)-3\times1$ 표면의 core-level spectrum에서의 두 표면 peak의 존재와 그 위치는 같은 금속에 의해 유도된 $Si/Ge(111)-3\times1$의 경우와 유사하며, 이는 두 표면의 구조fl서의 유사성을 시사한다. $Li/Ge(111)-3\times1$ 표면의 core-level 광전자 스펙트럼에서 보이는 두 개의 표면 성분의 존재와 위치는 알칼리 금속으로부터 유도되는 $Si/Ge(111)-3\times1$의 구조 모형으로 제안된 honeycomb-chain 모형과 잘 일치한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.355-362
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• 2000

Neoplastic growth is characterized by alterations of oncogenes and antioncogenes. The interaction between activated oncogenes and functional deletion of antioncogene appears to be the driving force directing normal cells to uncontrolled growth resulting in tumor. In addition to those genes mentioned, other genes controlling the entry of cells into the cell cycle have recently been implicated in cancer development. The overexpression of the cyclin D1 gene, which has been mapped to 11q13, either by gene rearrangement or amplification has been noted in various malignant tumors. The product of the cyclin D1 gene forms a complex with cyclin-dependent protein kinases(CDK4) that governs a key transition in the cell cycle. The relationships between the overexpression of cyclin D1 assessed by immunihistochemistry and the amplification of the cyclin D1 gene by differential polymerase chain reaction(DPCR) using primers for dopamin D2 receptor gene in 13 cases of squamous cell carcinomas of the oral cavity have been studied. The semiquantitative assay of cyclin D1 amplification has been made by cyclin D1/dopamin D2 receptor(CD/DR) ratio. The results were as follows; 1. In the normal tissue and the tumor, the CD/DR ratios were 0.82 and 1.36 respectively. This implicates 1.65-fold amplification of cyclin D1 gene in tumor compared to that in normal tissue. 2. The tumor tissue which showed overexpression of cyclin D1 by immunohistochemistry revealed 2-fold amplification of cyclin D1 compared to the normal tissue. 3. The tumor tissue which showed mild expression of cyclin D1 by immunihistochemistry revealed 1.7-fold amplification of cyclin D compared to the normal tissue. 4. The cyclin D1 was overexpressed in the tumor tissue at the rate of 38%. Above results suggest that cyclin D1 has close correlation with the development of carcinoma in the oral cavity. But further studies were needed to elucidate the carcinogeneic mechanisms by comparative studies among cyclin D1, pRb and p53.

• 공업화학
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• 제5권3호
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• pp.451-456
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• 1994

천연계 비이온 계면활성제 APG(Alkyl Polyglucoslde)는 옥수수 성분의 글루코스와 팜, 야자유에서 얻어지는 지방 알코올을 이용하여 합성된다. 친수성인 글루코스의 중합도(D.P.=1.2~1.8)와 소수성인 alkyl chain 길이 (C8-C14)에 따른 계면특성(표면 계면장력, cmc, 기포력, effectiveness 등)을 조사한 바 중합도에는 영향이 적으나, alkyl chain 길이에는 큰 영향을 받았다. 지방산 오염에 대한 APG alkyl chain 길이별 세정력 평가를 한 결과 계면 장력이 낮을수록, 단위 면적당 흡착량이 많을수록 우수한 세정력을 나타내었으며, 그 순서는 APG 0814> APG 1214> APG 10> APG 0810> APG 08과 같다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.209-214
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• 2003

We developed a new type of human-sized BWR (biped walking robot), named KUBIR1 which is driven by the closed-chain type of actuator. A new type of the closed-chain actuator for the robot is developed, which is composed of the four-bar-link mechanism driven by the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of 6 D.O.F joints. For front walking, three pitch joints and one roll joint at the ankle. In addition to this, one yaw joint for direction change, and another roll joint for balancing the body are attached. Also, the robot has two D.O.F joints of each hand and three D.O.F. for eye motion. There are three actuating motors for stereo cameras for eyes. In all, a 18 degree-of-freedom robot was developed. KUBIR1 was designed to walk autonomously by adapting small 90W DC motors as the robot actuators and batteries and controllers are on-boarded. The whole weight for Kubir1 is over 90Kg, and height is 167Cm. In the paper, the performance test of KUBIR1 will be shown.

• 폴리머
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• 제26권4호
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• pp.439-444
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• 2002

n-Alkyloxy기를 가지는 4가지 종류의 서로 다른 benzilidene anhydrides (2a~d)를 4-(n-alkyloxy)benzaldehyde (1a,b)와 diethyl succinate와의 Stobbe condensation, 가수분해, 탈수고리화반응으로 이어지는 연속적인 반응을 통하여 성공적으로 합성하였다. 단량체의 화학적 구조를 분광학적 방법으로 분석하여 합성된 단량체 (2a~d)는 (Z,Z)-이성체로 존재함을 확인하였다. 중합은 질소분위기하 150~$210^{\circ}C$의 온도범위에서 괴상중합법으로 행하여졌다. 합성된 고분자의 화학적 구조와 열적 성질을 각각 분광학적 방법과 TGA, DSC를 이용하여 조사하였다. 합성된 고분자의 성질은 곁사슬의 길이에 따른 화학적 구조에 크게 의존함을 알 수 있었다.

• 한국축산식품학회지
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• 제44권4호
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• pp.951-965
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• 2024

Lactiplantibacillus plantarum is a valuable potential probiotic species with various proven health-beneficial effects. L. plantarum LM1001 strain was selected among ten strains of L. plantarum based on proteolytic activity on whey proteins. L. plantarum LM1001 produced higher concentrations of total free amino acids and branched-chain amino acids (Ile, Leu, and Val) than other L. plantarum strains. Treatment of C2C12 myotubes with whey protein culture supernatant (1%, 2% and 3%, v/v) using L. plantarum LM1001 significantly increased the expression of myogenic regulatory factors, such as Myf-5, MyoD, and myogenin, reflecting the promotion of myotubes formation (p<0.05). L. plantarum LM1001 displayed β-galactosidase activity but did not produce harmful β-glucuronidase. Thus, the intake of whey protein together with L. plantarum LM1001 has the potential to aid protein digestion and utilization.

• 생물정신의학
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• 제1권1호
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• pp.67-78
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• 1994

The author examined the relationship of two markers, D5S39(p105-153Ra), D5S76(p105-599Ha) of chromosome 5 and $D_2$, $D_3$ receptor genes in a Korean schizophrenic pedigree using polymerase chain reaction(PCR). The results were as follows : 1) On D5S39 locus, 5 different alleles(224/226 bp : 4 cases, 218/226 bp : 3 cases, 222/226 bp : 3 cases, 218/230 bp : 1 case, 222/224 bp : 1 case) were produced. 2) On D5S76 locus, 5 different alleles(102/112 bp : 4 cases, 94/112 bp : 3 cases, 108/112 bp 3 cases, 94/94 bp : 1 case, 102/108 bp 1 case) were produced. 3) On $D_2$ receptor gene, 3 different alleles($A_1A_2$ : 8 cases, $A_1A_1$ : 2 cases, $A_2A_2$ : cases) were produced. 4) On $D_3$ receptor gene, 2 different alleles(1/2 : 7 cases, 1/1 : 5 cases) were produced. The author had not find any specific alleles on all four loci in all pedigree nor any specific alleles in the schizophrenic patients. Though the author has not found absolute relationship between the four loci and the onset of schizophrenia, there still remains the possibilities if the more detailed and elaborated pedigree studies are done.