• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.476-476
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• 2011

Introduction of CNTs into a metal matrix has been considered to improve the mechanical properties of the metal matrix. However, the binding energy between metals and pristine CNTs wall is known to be so small that the interfacial slip between CNTs and the matrix occurs at a relatively low external stress. The interfacial strength between CNT and metal matrix is thus one of the key factors for successful development of the CNT/metal composites. Defective or functionalized CNT has been considered to enhance the interfacial strength of nanocomposites. In the present work, we design the various realistic hybrid structures of the single wall CNT/Cu complexes and characterize the interaction between single wall CNTs and Cu nano-particle and Cu13 cluster using first principle calculations. The characteristics of functionalized CNTs with various surface functional groups, such as -COOH, -OH, and -O interacting with Cu are investigated. We found that the binding energy can be enhanced by the surface functional group including oxygen since the oxygen atom can mediate and reinforce the interaction between carbon and Cu. These results strongly support the recent experimental work which suggested the oxygen on the interface playing an important role in the excellent mechanical properties of the CNT/Cu composite.

• 대한안전경영과학회지
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• 제21권4호
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• pp.67-74
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• 2019

Visual inspection is regarded as one of the critical activities for quality control in a manufacturing company. it is thus important to improve the performance of detecting a defective part or product. There are three probable working modes for visual inspection: fully automatic (by automatic machines), fully manual (by human operators), and semi-automatic (by collaboration between human operators and automatic machines). Most of the current studies on visual inspection have been focused on the improvement of automatic detection performance by developing a better automatic machine using computer vision technologies. However, there are still a range of situations where human operators should conduct visual inspection with/without automatic machines. In this situation, human operators'performance of visual inspection is significant to the successful quality control. However, visual inspection of components assembled into a mobile camera module belongs to those situations. This study aims to investigate human performance issues in visual inspection of the components, paying more attention to human errors. For this, Abstraction Hierarchy-based work domain modeling method was applied to examine a range of direct or indirect factors related to human errors and their relationships in the visual inspection of the components. Although this study was conducted in the context of manufacturing mobile camera modules, the proposed method would be easily generalized into other industries.

• Molecules and Cells
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• 제41권7호
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• pp.665-675
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• 2018

Rice is a facultative short-day (SD) plant in which flowering is induced under SD conditions or by other environmental factors and internal genetic programs. Overexpression of Histone Deacetylase 701 (HDT701) accelerates flowering in hybrid rice. In this study, mutants defective in HDT701 flowered late under both SD and long-day conditions. Expression levels of florigens Heading date 3a (Hd3a) and Rice Flowering Locus T1 (RFT1), and their immediate upstream floral activator Early heading date 1 (Ehd1), were significantly decreased in the hdt701 mutants, indicating that HDT701 functions upstream of Ehd1 in controlling flowering time. Transcript levels of OsINDETERMINATE SPIKELET 1 (OsIDS1), an upstream repressor of Ehd1, were significantly increased in the mutants while those of OsGI and Hd1 were reduced. Chromatin-immunoprecipitation assays revealed that HDT701 directly binds to the promoter region of OsIDS1. These results suggest that HDT701 induces flowering by suppressing OsIDS1.

• 한국동물생명공학회지
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• 제36권4호
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• pp.307-313
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• 2021

Traf4 (Tumor necrosis factor Receptor Associated Factor 4) is a member of the tumor necrosis factor receptor (TNFR) - associated factors (TRAFs) family. TRAF4 is overexpressed in tumor cells such as breast cancer and associated with cytoskeleton and membrane fraction. Interestingly, TRAF4 was localized with tight junctions (TJs) proteins including OCLN and TJP1 in mammary epithelial cells. However, the expression patterns and biological function of Traf4 were not examined in preimplantation mouse embryos although Traf4-deficient mouse showed embryonic lethality or various dramatic malformation. In this study, we examined the temporal and spatial expression patterns of mouse Traf4 during preimplantation development by qRT-PCR and immunostaining, and its biological function by using siRNA injection. We found upregulation of Traf4 from the 8-cell stage onwards and apical region of cell - cell contact sites at morula and blastocyst embryos. Moreover, Traf4 knockdown led to defective TJs without alteration of genes associated with TJ assembly but elevated p21 expression at the KD morula. Taken together, Traf4 is required for TJs assembly and cell proliferation during morula to blastocyst transition.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.551-559
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• 2000

An integrated on-line inspection system was constructed with seven cameras, half mirrors to split images, 720 nm and 970 nm band pass filters, illumination chamber having several tungsten-halogen lamps, one main computer, one color frame grabber, two 4-channel multiplexors, and flat plate conveyer, etc., so that a total of seven images, that is, one color image from the top side of an apple and two B/W images from each side (top, right and left) could be captured and displayed on a computer monitor through the multiplexor. One of the two B/W images captured from each side is 720nm filter image and the other is 970nm. With this system an on-line grading software was developed to evaluate appearance quality. On-line test results to the Fuji apples that were manually fed on the conveyer showed that grading accuracies of the color, defective and shape were 95.3%, 86% and 91%, respectively. Grading time was 0.35 sec per apple on an average. Therefore, this on-line grading system could be used for inspection of the final products produced from an apple sorting system.

• 한국도서관정보학회지
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• 제54권3호
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• pp.1-32
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• 2023

이 연구의 목적은 2009년부터 본격적으로 추진되어온 도서관정책의 성과와 한계를 지역 공공도서관정책의 건강성에 대한 점검을 통해 가늠해 보는 데 있다. 이를 위해, 지역 공공도서관정책의 법적 근거가 되는 도서관 조례와 내용적 길잡이가 되는 시행계획부터 점검하였다. 이어서 기존 정책이 지역 공공도서관에 가져온 긍정적 변화와 그 이면에 공존하는 부정적 모습을 밝혀내었다. 마지막으로, 기존 정책에 내재하는 구조적 한계에 집중하면서 정책의 건강성을 제고하기 위한 실사구시적인 처방을 모색하였다.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.415-424
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• 2010

The purpose of this study was to investigate the relationship between the global regulatory mechanism known as quorum sensing and expression of virulence factors in Escherichia coli O157:87. A nonpolar luxS deletion was introduced into the chromosome of strain CI03J, a human clinical isolate from South Korea, to create the ${\Delta}luxS$ mutant strain ML03J. Phenotypic characterization of wild-type and mutant strains demonstrated that ML03J had no obvious growth or metabolic defects on 0.2% glucose LB medium, produced a functionally defective flagellum, and could not utilize sorbose; the biological significance of sorbose utilization is unknown. Omics-based analysis revealed the involvement of LuxS in the transcriptional activation of several flagella/chemotaxisrelated genes (flhD; fliA, C, D, S, Z; and cheA, Y, Z), repression of glutamate-dependent acid resistance genes (gadAB), and expression of virulence factors including Shiga toxin, hemolysin, and SepD within the LEE pathogenicity island.

• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.35-39
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• 2020

Nonwet (Head in Pillow) 불량은 SMT(surface mount technology) 공정 불량 유형 중 하나로 이 불량은 solder paste misalign, reflow 조건, package warpage, package ball size 등과 같은 인자에 따라 불량이 발생을 한다. 이에 본 논문은 Nonwet 발생 인자 중 ① reflow 조건 ② package ball & solder paste misalign ③ package ball 크기 type에 대한 인자를 선정하여 nonwet 실험을 진행하였다. 먼저 reflow 조건의 경우 soldering 시간이 길 경우 nonwet risk가 증가를 하나, reflow 공정에 N₂를 적용할 시 solder ball 산화 억제에 따른 nonwet 개선을 확인 할 수 있었다. 또한 package ball과 solder paste misalign 발생 시 ball과 paste의 접촉 깊이가 20 ㎛ 이하의 경우 nonwet에 취약 했으며, package ball 체면적이 작을수록 nonwet 관점 개선됨을 확인 할 수 있었다.

• 무역상무연구
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• 제40권
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• pp.3-30
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• 2008

This article attempts to describe and analyze the rules on the buyer's remedies for lack of conformity under PELS. It shows that such remedies under the PELS operate in a two-tier remedial scheme which is alien to both domestic and international legal systems. That is, repair and replacement take the position of primary remedy, whereas termination, price reduction and damages are secondary remedies which are available only where the primary remedies cannot be invoked. Notwithstanding its superiority, the PELS have some drawbacks in several aspects. First, the PELS seems to place its focus on the factor of cost except the other factors, for instance, the significance of the lack of conformity, when one decides whether the first tier remedies cause the seller unreasonable effort or expense. It is argued that the factors can be considered by referring to art. 1:302 PECL. Second, the PELS does not expressively provide any exclusion of the seller's right to choose between repair or replacement on the basis of unreasonable uncertainty in reimbursing the expenses advanced by the buyer. It argues that if there is such uncertainty, it should be regarded as causing the buyer an unreasonable inconvenience under art. 4:204(1). Third, the PELS does not seem to properly reflect the consumer's interests in that most consumers prefer to have the absolute right of termination as against the commercial sellers who have a relatively stronger bargaining position. The reasons for that is that there is a big hurdle, i.e., a hierarchy of remedies, to be overcome by the consumer to battle with the commercial seller, and that unavoidable vagueness in defining a minor lack of conformity has been often used against the consumer, but in favour of the commercial seller with a strong bargaining position.

• 패션비즈니스
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• 제2권4호
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• pp.102-111
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• 1998

The purpose of this study is to present the basic material for the competitive, high-quality products by analyzing employees' attitude toward their job and some factors which influence the enhancement of productivity, education of workers, and facilities. This project was mainly conducted the conditions of women's wear manufacturing industries in Taegu by interviewing 143 employees in the sewing department. The result of this dissertation can be summarized as follows; 1. When it comes to the division of task in the sewing department, one team is composed of chairpersons (33.5%), assistant members (27.4%) and sub-assistant members (26.6%). The inspection of commodities as well as the enhancement of work on ironing for elaboration was divided as completion (12.6%) and finally the forms of task were made up of design sampling team (49%) and contracting team (51%). 2. Among the needle workers, as many as 60% employees had received technical education, which was by means of being passed down from the predecessors (81.6%). In terms of the period of education, from 2 to 5 years topped the list. The contents of education comprise patterning, sewing (65.2%) and ironing (20.3%). 3. The department of design takes charge of the report on working directions up to 88.2% and the working directions were used by 69.9 % of technicians. The directors of working conditions and methods were chiefs of designing department (37.7%) and those of sewing department (30.8%). The factors of defective goods were low-quality materials (50.0%), the deficiency in skills of workers. In terms of methods for preventing defects, technical education of workers, standardization of task and investment for factory automation were suggested. 4. As for their perception of present work, most of employees (80%) look upon it as a way of earning a living and 11% of them wanted to derive many things from their work. 59.2% of workers were satisfied with the product. When it comes to the incentive system provided by company, 67.0% responsed that it was not bad, and 23.9% evaluated it as 'satisfactory'.