• Journal of Embryo Transfer
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• v.16 no.1
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• pp.61-68
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• 2001

Sperm competent for fertilization can become capacitated, bind to the zona pellucida (ZP) of an egg in a specific manner, and complete acrosomal exocytosis. Failure to carry out these functions results in infertility. Although the interactions between the ZP and the plasma mem-brane overlying the sperm acrosome have been considered important for sperm-egg recognition and signalling, recent results have prompted a reassessment of current paradigms concerning these interactions. In this review, we're going to discuss about the roles of the acrosomal matrix, the particulate component of the acrosomal contents, in fertilization. The general hypothesis is that acrosomal exocytosis leads to the exposure of acrosomal matrix proteins that become de-facto extracellular matrix (ECM) on the surface of the sperm head, and that the dynamic interactions of this newly-exposed sperm ECM with the egg ECM (the ZP) govern sperm-egg recognition and sperm penetration of the ZP Informations from these experiments may provide new ways to address the poor ZP binding of sperm from some human infertility patients and may offer new avenues for contraception through the disruption of purposeful sperm-ZP binding.

• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.251-262
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• 1999

In the automated manufacturing systems, the problem regarding how to make production activities flexible is even more important and critical than that regarding how to product large quantities, and the more flexible, if possible, the manufacturing system is, the more competitiveness and profitable factors it gets. This research, therefore, concentrated on establishing the flexibility and evaluating performance on the manufacturing system, operational flexibility is considered because of enabling the manufacturing system to get both the improvement of production rate and the adaptive ability of environment changes. For it, we used the analytical tool, GSPNs, which is a kind of timed Petri-Nets. GSPNs is competent enough to consider practical situations just like operation priorities, machine failure, randomness, concurrency and so on. Through the GSPNs analysis, it is confirmed that in the manufacturing system with operational flexibility is compatible with the traditional performances such as production rate or mean waiting time.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.93-94
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• 2001

Former studies dealing with combined effects caused by chemical compounds in the metabolically competent hepatoma cell line Hep G2 indicated that Hep G2 cells are useful and sensitive indicators for the identification of synergisms of promutagens, comutagens and antimutagens which are relevant in eukryontic (human) cells. In the present study we examined the modulation of DNA damages by the suspected antimutagens ascorbic acid, beta-carotene, alpha-naphthoflavone and beta-naphthoflavone in Hep G2 cells.(omitted)

• Economic and Environmental Geology
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• v.13 no.4
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• pp.241-246
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• 1980

Some components in uranium-bearing formations which consist mainly of black shale, slate. and low grade coal-bearing formation of Ogcheon Belt were processed statistically in order to find out the geochemical correlations with uranium. Geochemical enrichment of uranium, vanadium and molybdenum in low grade coal-bearing formations and surrounding rocks is remarkable in the studied area. Geochemical correlation coefficient of uranium and molybdenum in the rocks displays about 0.6, and that of uranium and fixed carbon about 0.4. Uranium and vanadium in uranium-bearing low grade coals denote very high correlation with fixed carbon, which is considered to be responsible for enrichment of metallic elements, especially molybdenum. Close geochemical correlation of uranium-molybdenum couple in the rocks can be applied as a competent exploration guide to low grade uranium deposits of this area.

• Journal of Construction Engineering and Project Management
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• v.5 no.2
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• pp.35-43
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• 2015

Project Management Consultant (PMC) plays a vital role in the overall performance of any project. Selecting right PMC for right project is the most crucial challenge for any construction owner. Thus, PMC selection is one of the main decisions made by owners at the early phase of construction project. It is not easy for the project owner to select a competent PMC due to the fuzziness, imprecision, vagueness, incomplete and qualitative criteria of the decision. This paper presents a model for selecting PMC contractor using the Fuzzy Analytical Hierarchy Process (FAHP). And a fuzzy number based framework is proposed to be a viable method for PMC contractor selection. A case study to illustrate the application of the model is also presented in this paper.

• The Journal of the Korean dental association
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• v.56 no.7
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• pp.376-384
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• 2018

The most valuable site of laser treatment is analgesic effect and fast healing process. If we understand an use this advantage correctly, it will helpful in relationship with patients and hospital management. So this study reported clinical cases about laser used in esthetic treatment with literature review. Periodontal treatment using laser was taken for patient who complain about gingival swelling during orthodontic treatment. And, esthetic plastic treatment using laser for alveoar reduction was taken for patient who complained about esthetic problem of maxillary gingiva. The treatment using laser can shorten the inconvenience and complicated treatment process and minimize patient's fear and discomfort during treatment procedure. So patients and clinicians can expect competent result in clinical cases. The laser for esthetic treatment was valuable.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.13-24
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• 1998

This study aims at examining the safety of the would-be approach channel of LNG Terminal at Kwangyang Harbour, by utilizing Captains 2000 port-design simulator. Six competent shipmasters or navigators participated in this study. The developed model ship was a 70,200DWT (138,000m3) LNG carrier. The environmental conditions were maximum flood-and-ebb current condition and wind condition. To evaluate the navigational safety, two categories were analyzed, which were measures of vessel's proximity and shiphandler's subjective evaluations. With respect to the effects of the worst environmental conditions on transit safety, it was concluded that the would-be approach channel was safe on basis of the support of four tugs of 3,200hp or more and current speed of 0.5knots or less.

• Journal of Plant Biology
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• v.37 no.3
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• pp.365-370
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• 1994

Excised cotyledon segments of ginseng zygotic embryos at various developmental stages were cultured on MS basal medium from which somatic embryos were directly induced. The frequency of somatic embryo formation on the segments declined with the advancing zygotic embryo maturity. All of the cells in the cotyledons of immature zygotic embryos were smaller and more densely cytoplasmic than those in mature embryos. Histological examinations revealed that the poly-somatic embryos formed on immature embryos were of multi-cell originand derived from the epidermal and subepidermal cell layers. However, in the cotyledon of germinating zygotic embryos, only theepidermal cells were densely cytoplasmic and singularly competent to develop into somatic embryos resulting into single embryos at a frequency of 100%.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.1-6
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• 2005

This study is to investigate empirically the turnover awareness of key member working in Research & Development Division in high technology electronic R&D institute. Through the analysis of 106 questionnaires and individual depth interview with key member who is evaluated as core researcher and developer in their working project or has good results in the last 2-3 years, this study obtains the practical informations on the understandings of their professional consciousness and extend of turnover awareness etc. The findings are as follows. Two-thirds of the researcher has the mind of turnover to improve job stability and develop their career. They have an self-awareness that they are key member as a core competent person in working project and their organization, but are dissatisfied with the underestimation of their performances that are not recognized by the organization as they expected level. And the result indicates that many of them haven't find their visions in their organization.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.233-239
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• 1999

To develop the potential use as new host strain for gene cloning the optimal conditions for transform-ation of alkali-tolerant Bacillus sp. were examined. The Bacillus sp. YA-14 was cultured to late logarith-mic growth phase at 37$^{\circ}C$ in modified SPI medium (pH8.0) containing 0.4% MgSO4 0.5mM CaCl2 1 ml of competent cell was mixed with 0.5$\mu$g of plasmid DNA and incubated with shaking at 37$^{\circ}C$ for 40min. The transformation frequency under the optimal condition was 4.53$\times$10-6 CFU/ml/g plasmid DNA. The electrophresis and stably maintained in the new host.