• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.55-62
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• 2003

This paper investigates the micro-cutting of cemented carbides using PCD (polycrystalline diamond) and PCBN (polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was studied, including cutting speed, depth of cut and various tool rake angle. Summary of the results are shown below. (1) Three type of chip formation process have been proposed by the results of the direct observation in orthogonal micro-cutting of cemented carbide materials. (2) From the whole observation of chip formation, primary WC particles are crushed and/or fine grained in the shearing deformation zone. A part of them are observed to collide directly with a cutting edge of tool by following the micro-cutting. (3) Surface finish, surface morphology and surface integrity is good to obtain by cutting with PCD cutting tool compared with PCBN. (4) The machined surface has the best quality near the low cutting speed of 10${\mu}m$/sec with a cutting depth of 10 ${\mu}m$ using 0$^\circ$ rake angle and 3$^\circ$ flank angle in this condition, but it was found that excessively low speed, for example the extent of 1 ${\mu}m$/sec, is not good enough to select for various reason.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.13
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• pp.105-129
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• 2000

INCOTERMS 2000 was not changed in its basic system but much improved in many minor aspects, reflecting the expansion of customs free zone, the spread of electronic communications and the changes of transportation practices. Among many points, following revisions are to be considered important to examine : First, the term 'delivery' is clearly defined in the preamble of each term, which is very significant since the risk is connected with the delivery in international trade. Second, the obligation of carrying out export customs formalities in FAS and import customs formalities in DEQ are imposed to seller and buyer respectively according to current trade practices. Third, since the customs formalities are no more needed among the countries of customs free zone, the phrase 'where applicable' is inserted in A.2 and B.2 of each term. Fourth, the method of delivery(for example, loaded or unloaded) became very concrete and clear in each term. Fifth, in the obligation of buyer's contracting insurance, the 'no obligation' is added even though the buyer has no insurance obligation to the seller. Finally the I.C.C. tried to make unification of the special terminologies be in accordance with those of CISG to achieve international harmony between the uniform law and uniform usages.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.281-284
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• 2008

The purposes of this study were to make clear the present condition of indoor thermal environment in apartment units and to analyze the relation of the living factors with indoor thermal elements. The field surveys consisted of measurements on physical elements and observations on living factors and interview on resident's subjective responses were carried out in 20 apartment units. The field surveys were carried out during the $January{\sim}March$ 2007. Measuring elements were air temperature, globe temperature, and relative humidity. As results, the averages of indoor temperature each houses were $21.2{\sim}27.2^{\circ}C$, the number of houses exceed the comfort zone were 4. The averages of globe temperature each houses were $21.3{\sim}27.5^{\circ}C$, 6 houses exceeded the comfort zone. The means of relative humidity were $19.5{\sim}58.8%$, relatively dry condition. The clothing value of residents were $0.39{\sim}0.89$ clo(average 0.68 clo). The average of thermal sensation ratings each room were $4.2{\sim}4.8$, 'neutral'$\sim$'slightly warm'. The results of regression analysis on relations of living factors with the thermal elements are as follow; ventilation time(outdoor air exchange), door opening time with balcony, and gas cooker use time had significant effect on indoor temperature.

• Mycobiology
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• v.39 no.2
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• pp.129-132
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• 2011

To determine the optimal media conditions for the detection of the extracellular cellulase activity in Ganoderma neo-japonicum, we varied three media conditions: dye reagent, pH, and temperature. We evaluated the use of four dyes, Congo red, phenol red, remazol brilliant blue, and trypan blue. To observe the effect of pH on the chromogenic reaction, we tested media ranging from 4.5 to 8.0. To research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35^{\circ}C$. On the whole, the best protocol called for Ganoderma neo-japonicum transfer onto media containing Congo red with a pH of 7.0, followed by incubation at $25^{\circ}C$ for 5 days. Our results will be useful to researchers who study extracellular enzyme activity in Ganoderma neo-japonicum.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.181-186
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• 2001

In this study, we observed air temperature to make clear that land coverage condition and forest form has a certain relationship to air temperature in a day in various green space. And with revolution analysis, interpreted relationship of air temperature distribution in the green space, of land coverage rate and air temperature, of volume of tree and temperature. With this experimental result, propose green plan, taking into consideration lower effect of air temperature. In this result lower zone is formed in forest and water area, higher zone is done in paved surface and barren ground. And arbor＋subarbor area, water area sur-rounded forest and small river is formed relative lower air temperature. In my opinion to promote efficiency lower air temperature area, it is need to make water area surrounded forest, to make forest form lower air temperature 2∼3 layer forest. Lower air temperature effect is in order of arbor, subarbor, shrub and is proportioned increasing of tree.

• Mycobiology
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• v.37 no.4
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• pp.313-316
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• 2009

To determine the optimal medium conditions for the detection of the cellulolytic activity in Ganoderma lucidum, we varied three media conditions: dye reagent, pH, and temperature. First, we evaluated the use of four dyes, Congo Red, Phenol Red, Remazol Brilliant Blue, and Trypan Blue. To observe the effect of pH on the chromogenic reaction, we also made and tested various media spanning acidic and alkaline pHs, ranging from 4.5 to 8.0. Furthermore, in order to research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35{^{\circ}C}$. On the whole, the best protocol called for Ganoderma lucidum transfer onto media containing Congo red with pH adjusted to 7.0, followed by incubation at $25{^{\circ}C}$ for 5 days. Our results will be useful to researchers who aim to study extracellular enzyme activity in Ganoderma lucidum.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.242-255
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• 2019

In this study, we examined the antimicroboal effect against Actinobacillus actinomycetemcomitans and Prevotella intermedia which were the bacteria causing the Periodontopathic by using 34 types of natural plant extracts. Therefore, this study measures growth inhibition activity and Minimum Inhibition Concentration (MIC) of a sample extract with the use of organic solvent extracts in order to analyze the antibacterial effect of natural plant extracts on periodontopathic bacteria. Each of the 34 types of natural plant extracts were extracted by using the ethanol, and subsequently, the size of growth inhibition zone(clear zone, ㎜) of respective extracts were measured through the disk diffusion method. As a result, it was found that the growth inhibitory activity was found for A. actinomycetemcomitans, which is the bacteria causing the Periodontitis, in 13 types of natural plant extracts such as Raphanus sativus, Akebia quinata, Paeonia lactiflora, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Forsythia saxatilis, Gentiana macrophylla, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus, etc. In the case of P. intermedia, the growth inhibitory activity was found in 13 types of natural plant extracts such as Raphanus sativus, Angelica acutiloba, Akebia quinata, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Cinnamomum cassia, Aster tataricus, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus etc. For A. actinomycetemcomitans, anti-bacterial effect was exhibited in Belamcanda chinensis, Cinnamomum cassia, Kalopanax Pictus, Phellodendron amurense, Coptis chinensis. The Coptis chinensis showed the most excellent growth inhibitory activity in all organic solvent fragment, while P. intermedia showed the growth inhibitory activity in Belamcanda chinensis, Cinnamomum cassia, Meliaazedarach, Phellodendron amurense, and Coptis chinensis.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.41-51
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• 2005

Objectives : The purpose of this research was physiological activities, cytotoxicity, and antibacterial activities of the Cheongyeolsodokum and its constituent herbs. Methods : Physiological activities, cytotoxicity, and antibacterial activities were examined through the Cheongyeolsodokum and its constituent herbs. Results : In the physiological activities, the electron donating ability(EDA) of the water and ethanol extracts from the Cheongyeolsodokum were over 60% and 80% at 100 ppm, respectively. The EDA of the water and ethanol extract from the Cheongyeolsodokum ingredients were gradually increased as well. Water and ethanol extracts from the Cheongyeolsodokum and its constituent herbs inhibited xanthine oxidase activity, they showed superoxide dismutase(SOD)-like activity. The Cheongyeolsodokum and its constituent herbs inhibited cancer cell growth in a dose-dependant manner. Also, the clear zones against Staphylococcus aureus and S. epidermidis were clear shown at 2.5 and 5 mg/disc. Its constituent herbs showed the clear zone against various bacteria such as Candida albicans, S. aureus, S. epidermidis, and S. mutans were shown at 0.5 and 1mg/disc. Conclusions : We observed physiological activities, cytotoxicity, and antibacterial activities of the Cheongyeolsodokum and its constituent herbs. The results also indicated that water extract and ethanol extract of Cheongyeolsodokum and its constituent herbs can be used as a natural ingredient in food or cosmetic industry.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.223-236
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• 2019

Resistivity surveys can identify the distribution of geological units and structures (including fragmented fault zones), the extent of weathered and modified geological strata, and the characteristics of groundwater. This study aims to analyze the underground sedimentary layers and geological structures near the Nari and Albong Basins of Ulleung-do, Korea, focusing on six survey lines to identify the spatial trends in subsurface resistivity. A modified dipole array method (D method) was employed, combining resistivity results obtained by existing dipole array methods (A and C methods). The modified method provides optimal analysis of the cross-section of underground resistivity, and shows a clear boundary between a low-resistivity zone (${\leq}500{\Omega}{\cdot}m$) of sedimentary layers and weak zones, and a high-resistivity zone (${\geq}5,000{\Omega}{\cdot}m$) of volcanic rock (trachyandesite). The estimated average thickness of the sedimentary layers is 50~100 m for the Albong Basin and 100~200 m for the Nari Basin. An anomaly zone, different from the weak zone in the bedrock, is identified as a caldera fault, and the low-resistivity zone extends from the surface down to the lowest survey depths.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.647-657
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• 2018

This study was carried out to review as criteria for zoning at management plan for river restoration, in case of naturalness of river environment and suitability of water friendly activity suggested at assessment system of river environment in Korea. As a result of reviewing law and guidelines concerned, historic & cultural resources used as criteria for preservation zone, it was judged that the historical and cultural value as the preservation zone needs to be examined in connection with waterfriendly activity zone. In this study, we propose a sequential evaluation method to distinguish the waterfriendly activity zone by applying suitability of waterfriendly activity reflecting land use social characteristics, followed division of preservation and restoration zone at the first stage by the naturalness of river environment reflecting the natural environmental characteristics as a result of application to the test bed, Gap and Yudeung streams. In particular, it was concluded that the results of the present study provided more clear criteria for the problem that the last criteria for zoning did not reflect the difference between the left and the right side of stream, or the designation of the excessive water friendly zone. On the other hand, the criteria for designation in this study reflect the characteristics of various river environments as well as the setting of assessment unit based on the physical characteristics of rivers, and other legal regulations and local situations should be adjusted and supplemented in administrative procedures.