• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.275-280
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• 2001

Recently, the trends of industrial products grow more miniaturization, variety and mass production. Micro drilling which take high precision in cutting work is requested more micro hole and high speed working. Especially, Micro deep hole drilling is becoming more important in a wide spectrum of precision production industries, ranging from the production of automotive fuel injection nozzle, watch and camera parts, medical needles, and thick multi-layered Printed Circuit Boards(PCB) that are demanded for very high density electric circuitry. This paper shows the tool monitoring results of micro drill with tool dynamometer. And additionally, microscope with built-in monitor inspection show the relationship between burr in workpiece and chip form of micro drill machining.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.3
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• pp.210-216
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• 1984

An investigation of the effects of the size of mixing region determined by changing the position of fuel injection has been carried out. Measurements were made: the distribution of temperature and concentration profiles of the stable gas species, nitrogen oxide and total hydrocarbon in the flames. The results of this investigation show that variations of the size of mixing region produce major changes to the three type flow fields which significantly influence pollutant (NO, CO and THC) formation and energy release.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.485-491
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• 1999

A burr is formed in every corner of parts as a result of machining, which produces undesirable edge geometry and influence deeply to surface quality of workpiece. Therefore these burrs must be removed certainly. The cost of removing these burrs is directly proportional to their size. Burrs have been among the most troublesome obstruction to high productivity and automation of machining processes. The proper selection of cutting condition and tool geometry will be helpful to reduce the occurrence of burrs. In paper will observe burr formation along helix angle in end milling and certificate experimentally mechanics relation of helix angle and burr formation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.353-358
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• 1995

The emission characteristics of a semi-Bunsen type burner for gas boilers were studied experimentally. The experimental results reveal that nitric oxide emission increases with fuel flow rate. It is linearly proportional to total fue flow rate at a small amount of fuel up to 0.4 liters per minute. It does not change significantly within the range of fuel flow rate from 0.4 to 1.2 liters per minute per nozzle and increases at large fuel flow rate. The carbon monoxide emission reveals to be dependent upon the fuel flow rate per each nozzle and the number of fuel injection nozzles. Diameter of an injection nozzle could have an effect on the emission characteristics of this type of burners. However, there is no marked change in the nitric oxide emission if the total fuel flow rate is same with different nozzle sizes.

• Korean journal of applied entomology
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• v.14 no.4 s.25
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• pp.185-192
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• 1975

Various plant species, as many as 145 species in 43 families, were tested for susceptibility to the ordinary strain of the cucumber nosaic virus for two years from 1973 to 1974. Inoculations were made by mechanical method using carborundum. Plants in 71 species belonging to 27 families were infected. Of these species, systemic mosaic developed on the new leaves of plants in 57 species belonging to 24 families. Twenty-four species of plants, previously not reported as hosts of the CMV, were found to be infected in this experiment. These are Stellaria aquatica, Achyrauthes japonica, Agerratum houstonianum, Centipeda minima, Gillardia pulchella, Henisteptalyrate, Ixeris dentata, Saussurea uchiyamana, Brassica campestris, Lepidiumapetalum, Lobelia chinensis, Chenopodium bryoniaefolium, Carex neofilipes, Acalypha austalis, Amphicarpaea edgeworthii, Lotus corniculatus var japonicus, Phaseolus angularis, Sedum aizoom var heterodontum, Mosla punctulata, Perilla frutescens var japonica, Teucrium japonicum,. Linum usitatissimum, Mazus japonicus, Verbena hybrida. Twenty-three species reported to be susceptible by previous workers, but negative results were obtained in our experiment with Allium cepa, Celosia cristat, Daucus carota var. sativa, Artemisia asiatica, Callistenphus chinensis, Erigeron canadensis, Helianthusannuus, Tagetes eracta, Impatiens balsamina, Raphanus sativus, Ipomea batatas, Glycine max, Phaseolus vulgaris, Lilium longifolium, Papaver gomniferum, Sorghum vulgare, Triticum aestivum, Zea mays, Rumex coreanus, Potulaca grandiflora.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.9-17
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• 1990

Erwinia carotovora subsp. carotovora, Pseudomonas viridiflava and Pseudomonas marginalis pv. marginalis were tested for their pathogenicity to 35 kinds of domestic flowering plants. Among them, the following domestic flowering plants showed clear symptoms. 1. Erwinia carotovora subsp. carotovora : (Needle inoculation). Carnation(Dianthus catgophylius L.), madagascar periwinkle(Vinca rosea L.), flower gentle(Amaranthus tricolor L.), snapdragon(Antirrhinum majus L.), chrysanthemum(Chrysanthemum morifolium Ram.), mexiacan ageratum(Ageratum houstonianum Mill), china aster(Callistephus chinensis), youth and old age(Zinnia elegans Jacq.), common nasturtium(Tropaeorum majus L.), scarlet sage(Salvia splendens F.), dahlia(Dahia hybrida), pot marigold(Calendula officinalis L.), begonia treevine(Cissus dicolor Blume), cosmos(Cosmos bipinnatus Cav.), globe amaranth(Gomphrena globosa L.), black eyed susan(Thumbergia alata Bojer), common gypsophila(Gypsophila elegans Bieb.), ghent gladiolus(Gladiolus gandavensis Van.), indian shot(Canna orchiodes Bailey), iris(Iris nertschinskia Lodd), cyclamen primula(Dodecatheon meadia L.), scarlet kafir lily(Clivia miniata Regel.), flowering cabbage(Brassica oleracea L.). (Spray inoculation). Carnation, madagascar periwinkle, flower gentle, snapdragon, common nasturtium, ghent gladiolus, indian shot, cyclamen primula. 2. Pseudomonas viridiflava : (Needle inoculation). Carnation, madagascar periwinkle, snapdragon, chrysanthemum, cockscomb, mexican ageratum, china aster, common nasturtium, common petunia(Petunia hybrida Vilm), pot marigold, begonia treevine, cosmos, black eyed susan, common gypsophila, ghent gladiolus, indian shot, cyclamen primula, scarlet kafir-lily, flowering cabbage. (Spray inoculation). Common nasturtium, ghent gladiolus, indian shot, cyclamen primula. 3. Pseudomonas marginalis pv. marginalis : (Needle inoculation). Carnation, madagascar periwinkle, flower gentle, snapdragon, cockscomb, mexican ageratum, youth and old age, common nasturitium, common petunia, sweet william(Dianthus barbatus L.), pot marigold, begonia treevine, cosmos, common gypsophila, ghent gladiolus, indian shot, iris, cyclamen primula, scarlet kafir-Lily, flowering cabbage. (Spray inoculation). Common nasturtium, ghent gladiolus, indian shot, cyclamen primula.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.255-267
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• 1996

The so-called Cultural and Historical Geography, sometimes called even as the Historical and Cultural Geography, has been defined as an interdiscipline that encompasses several disciplines in Korea. Scholars with various academic background have participated in the academic activity of the Association of Korean Cultural and Historical Geographers that was organized in the late 1980s. The academic majors of these participants are cultural geography, historical geography, history of geography, urban geography rural geography, economic geography, social and economic history anthropology, landscape architecture, and so on. It was in the 1960s that articles about the Cultural and Historical Geography appeared for the first time in the major academic journals in Korea. The pioneers of publishing these articles in the 1960s continued to conduct their research, while training students majoring in the Cultural and Historical Geography in the 1970s. All of these pioneers and their students were very active in the formation of identity vrith the Cultural and Historical Geography In the 1980s. Cultural and Historical Geography in Korea took a great leap forward both in quantity and in quality. The number of articles in the journal increased substantially, and the range of research theme and methodology extended in a great deal. It was also in the late 1980s that the Association of Korean Cultural and Historical Geographers was organized in Seoul, Korea, and this association began to publish a professional journal named Cultural and Historical Geography once a year. In the 1990s, single-authored books dealing with Korean Cultural and Historcial Geography began to appear in public as textbooks or research monographs. These books are expected to speed up the spread of Cultural and Historical Geography in Korea. If it continues to grow further both in quantity and in quality as it has been, Cultural and Historical Geography in Korea will be able to stand as an independent academic field in the future. Until then, however, it cannot but avoid its mission to contribute to an integrated development of human geography in Korea. It has already gained not only its own merit in the humanistic perspective but also its own strength in its synthetic understanding.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.45-54
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• 2000

The effect of electropolishing far stamped leadframe on the removal of the edge burr and residual stress relief was examined. The present study showed that the electropolishing could be used for enhanced surface quality of stamped leadframes. The electropolishing was performed at the condition of 60% phosphoric acid electrolyte, 5 ampere of current and 3 cm electrode gap at $70^{\circ}C$ for 2 minutes for Alloy42 type leadframe, and $50^{\circ}C$ for 1.5 minutes for C-194 type leadframe. The FWHM values from X-ray diffraction showed that residual stress of electropolished leadframe recovered to the level of as-received raw materials and surface roughness measured by using AFM tuned out to be improved by 0.079 $\mu\textrm{m}$ and 0.014 $\mu\textrm{m}$ ($R_{rms}$) far alloy 42 and C-194 type leadframes, respectively. The plated thickness using XRF showed the improved uniformity in thickness variation by 0.4~0.5 $\mu\textrm{m}$ and grain growth, which is favorable for interface adhesion, was also observed from the bake test samples. We could certify dimensional stability of leadframe with inspection by means of 3D-topography and hardness measurements.