• Title/Summary/Keyword: product defect

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The effects of the surface defects on the hydroformability of extruded aluminum tubes (알루미늄 압출 관재의 표면 결함이 하이드로포밍 성형에 미치는 영향도에 관한 연구)

  • Kim D. H.;Kim B. J.;Park K. S.;Moon Y. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.247-250
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    • 2005
  • The need for improved fuel efficiency, weight reduction has motivated the automotive industry to focus on aluminum alloys as a replacement for steel-based alloy. To cope with the needs for high structural rigidity with low weight, it is forecasted that substantial amount of cast components will be replaced by tubular parts which are mainly manufactured by the extruded aluminum tubes. The extrusion process is utilized to produce tubes and hollow sections. Because there is no weld seam, the circumferential mechanical properties may be uniform and advantageous for hydroforming. However the possibility of the occurrence of a surface defect is very high, especially due to the temperature increase from forming at high pressure when it comes out of the bearing and the roughness of the bearing, which cause the surface defects such as the dies line and pick-up. And when forming a extruded aluminum tube, the free surface of the tube becomes rough with increasing plastic strain. This is well known as orange peel phenomena and has a great effect not only on the surface quality of a product but also on the forming limit. In an attempt to increase the forming limit of the tubular specimen, in the present paper, surface asperities generated during the hydroforming process are polished to eliminate the weak positions of the tube which lead to a localized necking. It is shown that the forming limit of the tube can be considerably improved by simple method of polishing the surface roughness during hydroforming. And also the extent of the crack propagation caused by dies lines generated during the extrusion process is evaluated according to the deformed shape of the tube.

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Study on the Siginificance and Importance of Preclinic Phase Theory(=mibyung) in Oriental Medicine (미병상태(未病狀態)의 학문적(學問的).임상적(臨床的) 중요성(重要性)과 의의(意義)에 대한 고찰(考察))

  • Lee Sun-Dong;Kim Myong-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.1 no.1
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    • pp.105-117
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    • 1997
  • The result of this paper runs as follows: 1. The theory of preclinic phase (=mibyung) was scientifically completed as one basic philosophy in "NAEKYUNG(內經)" and on influenced in the coming generations. Two principles for mibyung is to grow good energy and to avoid etiological cause. 2. So far oriental medicine has responded to already diseases, while to recognize the importance of mibyung is to convert it into preventive medicine which study and improve health. In spite of the opinion that no disease is health and no health is disease, the contrite of medical approch by the relative importance is necessary by understanding the steps of mibyung between health and disease with subdividing the steps of the occurance therefore, the scope of oriental medicine may be recognized from every disease to mibyung, that is, health. 3. Diagnosing and treating in the step of mibyung has more important meaning than suffering step because the checkup of mibyung means early examination and treatment. Mibyung can make an opportunity that improve scientific contradiction and defect of oriental medicine. However, scince the theory and practice lack the arrangement and study, much exertion and discussion is necessary.4. The diagnosis and cure in mibyung doesn't have many methods for treating, its index and standard isn't nified, and related theory is of small quantity. But the most prominent means of solution. with combination with other sciences and through the convertion into modem clinical examination, is to accomplish moderization, objectivity and indexation, etc. 5. The representive mibyungs are a hereditary disease, immune lack, mutation, early tumor, incubation of hepatitis and each infectious diseases, stress, etc. Since every science is the product of the times, it has the historical limits. As the times develop, the desire for good health is growing. Therefore we should consider above request in this times.

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Overexpression of human erythropoietin in tobacco does not affect plant fertility or morphology

  • Musa, Tamba A.;Hung, Chiu-Yueh;Darlington, Diane E.;Sane, David C.;Xie, Jiahua
    • Plant Biotechnology Reports
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    • v.3 no.2
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    • pp.157-165
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    • 2009
  • Human erythropoietin (EPO) is a leading product in the biopharmaceutical market, but functional EPO has only been produced in mammalian cells, which limits its application and drives up the production costs. Using plants to produce human proteins may be an alternative way to reduce the cost. However, a recent report demonstrated that overexpression of the human EPO gene (EPO) in tobacco or Arabidopsis rendered males sterile and retarded vegetative growth, which raises concern whether EPO might interfere with hormone levels in transgenic plants. In the present study, we demonstrated that overexpressing EPO with additional 5'-His tag and 3' ER-retention peptides in tobacco did not cause any developmental defect compared to GUS plants. With our method, all 20 transgenic plants grew on selective medium and, further confirmed by PCR, were fertile. Most of them grew similarly compared to GUS plants. Only one transgenic plant (EPO2) was shorter in plant height but had twice the life span compared to other transgenic plants. When 11 randomly selected EPO plants, along with the abnormal plant EPO2, were subjected to RT-PCR analysis, all of them had detectable EPO transcripts. However, their protein levels varied considerably; seven of them had detectable EPO proteins analyzed by western blot. Our results indicate that overexpressing human EPO protein in plants does not have detrimental effects on growth and development. Our transformation systems allow us to further explore the possibility of glycoengineering tobacco plants for producing functional EPO and its derivatives.

Shape-Simplification Analysis Model for Fatigue Life Prediction of Casting Products Considering Internal Defects (내부 결함을 고려한 주조 제품의 피로수명 예측을 위한 결함 형상단순화 해석모델)

  • Kwak, Si-Young;Kim, Hak-Ku
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.10
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    • pp.1243-1248
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    • 2011
  • Internal defects are a major concern in the casting process because they have a significant influence on the strength and fatigue life of casting products. In general, they cause stress concentration and can be a starting point of cracks. Therefore, it is important to understand the effects of internal defects on mechanical properties such as fatigue life. In this study, fatigue experiments on tensile specimens with internal defects were performed. The internal defects in the casting product were scanned by an industrial CT scanner, and its shape was simplified by ellipsoidal primitives for the structural and fatigue analysis. The analysis results were compared with experimental results for casting products with internal defects. It was demonstrated that it is possible to consider internal defects of casting products in stress and fatigue analysis. The proposed method provides a tool for the prediction of the fatigue life of casting products and the investigation of the effects of internal defects on mechanical performance.

An Application Study of Six Sigma in Clinical Chemistry (6 시그마의 적용에 대한 연구)

  • Chang, Sang Wu;Kim, Nam Yong;Choi, Ho Sung;Park, Yong Won;Chu, Kyung Bok;Yun, Kyeun Young
    • Korean Journal of Clinical Laboratory Science
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    • v.36 no.2
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    • pp.121-126
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    • 2004
  • The primary goal of six sigma is to improve patient satisfaction, and thereby profitability, by reducing and eliminating defects. Defects may be related to any aspect of customer satisfaction: high product quality, schedule adherence, cost minimization, process capability indices, defects per unit, and yield. Many six sigma metrics can be mathematically related to the others. Literally, six means six standard deviations from the mean or median value. As applied to quality metrics, the term indicates that failures are at least six standard deviations from the mean or norm. This would mean about 3.4 failures per million opportunities for failure. The objective of six sigma quality is to reduce process output variation so that on a long term basis, which is the customer's aggregate experience with our process over time, this will result in no more than 3.4 defect Parts Per Million(PPM) opportunities (or 3.4 Defects Per Million Opportunities. For a process with only one specification limit (upper or lower), this results in six process standard deviations between the mean of the process and the customer's specification limit (hence, 6 Sigma). The results of applicative six sigma experiment studied on 18 items TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA tests in clinical chemistry were follows. Assessment of process performance fits within six sigma tolerance limits were TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA with 72.2%, items that fit within five sigma limits were total bilirubin, chloride and sodium were 3 sigma. We were sure that the goal of six sigma would reduce test variation in the process.

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Performance Research of a Multi Functional Tree Protection Pad (다목적 기능을 가진 수목보호패드의 성능 연구)

  • Jung, Yong-Jo;Lee, Kyung-Yeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.1
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    • pp.133-143
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    • 2018
  • In spite of the growing importance of landscaping trees, the rate of flawed and withered trees damaged by pest, disease, drought or frost is increasing. In order to evaluate the performance of the Tree Protective Pad, which are developed to reduce the failure ratio in landscape planting, the tree protective pad for 'digging', 'pest controlling', and 'insulating' are tested based on the five functional criteria; moisturizing effect, wither preventive effect, pest and disease control, thermal effect, tensile strength, and environmental performance. The result of this study is as follows. The moisturizing effect of the tree protective pad for digging is found to be outstanding. According to the result of testing the pad on trees, in particular, it is better than jute tape in wither preventive effect, which means it is expected to prevent flaw and wilt from planting during the improper seasons like summertime. The experiment of installing the protective tree pad for pest controlling to the trunk of Quercus mongolica shows that preventive effect of the pad from diseases and insects is superior, and it also has economical effect by reducing the use of agricultural chemicals. The comparative test of the pad for insulating and jute tape proves that the temperature of the pad is about $2^{\circ}C$ higher than outside. The rate of tensile strength and biodegradation of the pad exceeds the optimal level, so it is revealed that the pad may be the work efficient and environment-friendly product. Likewise, by timely irrigating trees, the tree protective pad economically prevents trees from pest, disease,drought or frost, which may be caused by improper seasonal or delayed planting. As a means of reducing the flaw and facilitating the growth of trees, the exceptional performance of the pad is expected to effectively used in landscape planting and management.

The Development of Real-Time Free Length Monitoring Systems Interlocking with PLC Device (PLC 장비와 연동하는 실시간 자유장 모니터링 시스템 개발)

  • Jung, Jin-uk;Kim, Su-hong;Jin, Kyo-hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.539-541
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    • 2016
  • In this paper, we proposed real time free-length monitoring systems interlocking with the spring free-length sorter which shows the state of production connected to the spring production device. This systems enable the administrator to check the quality or quantity of product and the defect rate, etc., in the remote place. The proposed systems are comprised of the wireless device interlocking with PLC device, the server program, and user GUI program. The wireless device transmits the received data from PLC device to server program using Wi-Fi. Server program represents the data from the wireless device on the screen and insert those data into database. User GUI program shows data stored in database and supports the function which converts the stored data in DB to excel file.

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Feasibility Study the Assessment Factor of Quality Performance Index in Expressway Concrete Pavement (고속도로 콘크리트 포장에 대한 품질평가지수 평가인자의 적정성 검토)

  • Lee, Seung Woo;Kim, Gyung il;Ko, Dong Sig;Hong, Seung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.1
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    • pp.133-141
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    • 2017
  • Traffic volume increases according to highway expansion and industrial development which causes repetitive defect and durability degradation on pavement. The research of quality assurance system used abroad has introduced Korea. Korea Expressway Corporation (KEC) has developed a Quality Performance Index (QPI) that quantitatively assesses the level of quality of the final product, and practical applications. Assessment factor on concrete pavement consisted of pavement thickness, compressive strength, IRI and spacing factor. Assessment factor on concrete pavement is determined by empirical evaluation factor from abroad. In this study, analysis of evaluation factors of concrete pavement by using pavement life prediction simulation and measured data were evaluated with consideration of feasibility of the assessment factor. Pavement life, performance and durability are affected by pavement thickness, compressive strength, IRI and spacing factor in assessment factor on concrete pavement, QPI.

Case study of the large switching software metrics and their fault analysis (대형 교환 소프트웨어의 복잡성과 고장분석 사례 연구)

  • 이재기;남상식;김창봉;이규대
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.887-901
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    • 2002
  • Software management model divided into the software project model and design estimation model, software matrices model, reliability growth model, process improvement model(or process maturity model) etc. Among these software management models, software complexity model make an estimated of the product software. For a practice of software managed, need to guideline of the static analysis of software. Especially, Software complexity model introduced for the estimation of software quantity and program complexity. In case of measurement the software matrices, its need for us to analysis of software quality and products. On the other hand, we known that complexity program include many defects and consuming of source cost. So, we apply to complexity model using of the program complexity, control structure and volume matrices, interface metrics, process complexity metrics method. In this paper, we represent that the analysis of fault data detected during the system test. Also, we analysis of program control structure and interface, volume matrices in various aspect of switching software. Others, their results utilized similar of project and system development.

A Yeast MRE3/REC114 Gene is Essential for Normal Cell Growth and Meiotic Recombination

  • Leem, Sun-Hee
    • Journal of Microbiology
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    • v.37 no.4
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    • pp.248-255
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    • 1999
  • We have analyzed the MRE3/REC114 gene of Saccharomyces cerevisiae, previously detected in isolation of mutants defective in meiotic recombination. We cloned the MRE3/REC114 gene by complementation of the meiotic recombination defect and it has been mapped to chormosome XIII. The DNA sequence analysis revealed that the MRE3 gene is identical to the REC114 gene. The upstream region of the MRE3/REC114 gene contains a T_4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. Coincidentally, northern blot analysis indicated that the three sizes of MRE3/REC114 transcripts, 3.4, 1.4 and 1.2 kb, are induced in meiosis. A less abundant transcript of 1.4 kb is detected in both mitotic and meiotic cells, suggesting that it is needed in mitosis as well as meiosis. To examine the role of the MRE3/REC114 gene, we constructed mre3 disruption mutants. Strains carrying an insertion or null deletion of the MRE3/REC114 gene showed slow growth in nutrient medium and the doubling time of these cells increased approximately by 2-fond compared to the wild-type strain. Moreover, the deletion mutant (${\delta}$mre3) displayed no meiotically induced recombination and no viable spores. The mre3/rec114 spore lethality can be suppressed by spo13, a mutation that causes cells to bypass reductional division. The double-stranded breaks (DSBs) which are involved in initiation of meiotic recombination were not detected in the analysis of meiotic chromosomal DNA from the mre3/rec114 disruptant. From these results we suggest that the MRE3/REC114 gene product is essential in normal growth and in early meiotic stages involved in meiotic recombination.

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