• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.964-969
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• 1998

To investigated the anticarcinogenic activity of 70% ethanol extracts from various cereal in vitro, antimutagenic activity, inhibitory effect of DNA strand scission and tumor promotion were examined. The antimutagenic activity of the beans such as black bean and small red bean was generally higher than that of cereals examined. However inhibitory activity of 70% ethanolic extracts against DNA strand scission induced mitomycin C showed that millet, job's tear, black bean and soy bean among cereals and beans tested in this study inhibited effectively the DNA strand scission. Antioxidative activity of some cereal extracts determined by using linoleic acid model system showed that Job's tear, millet and black bean were higher antioxidative activity than other cereals and beans. Conventional short-term antipromoter assay system using activation of Epstein Barr virus (EBV) clearly demonstrated that sorghum, buckwheat, black bean and small red bean have inhibitory effects on promotion in cellular carcinogenesis.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.130-139
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• 2013

Construction accident rates are reflected in the pre-qualification of public construction projects in order to prevent accidents and facilitate the safety management of construction companies. However, the construction industry is still experiencing an increase in accident rates. Hence, there is a need to strengthen existing safety evaluation systems and requirements in public construction tendering. The objective of this study was to acquire and provide basic data for benchmarking to select tenderers in domestic public construction projects. In Singapore and Japan, safety evaluation systems and requirements are applied based on various aspects in order to screen tenderers. These evaluation systems include safety regulations and institutional requirements, as well as safety performance and safety management plans of respective construction projects. This study recommends that korean public construction projects also apply similar safety evaluation systems which include comprehensive safety criteria in order to decrease accident rates in the industry.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1288-1294
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• 1997

For screening antimutagenic effects, the effects of 95 medicinal plants on the mutagenicity of aflatoxin $B_1$ $(AFB_1)$ and benzo(a)pyrene [B(a)P] were investigated using the SOS chromotest with Escherichia coli PQ37. The mutagenicity induced by $AFB_1$ or B(a)P was reduced over 26% by 2 kinds and 8 kinds of medicinal plant, respectively. Eight plants (Bupleurum falcatum, Corydalis ternata, Gasfrodia elata, Ostericum koreanum, Pinellia ternatia, Poncirus trifoliata, Prunus armeniaca and Rehmannia glutinosa) were also shown to have inhibitory effects on both $AFB_1$ and B(a)P. The mutagenicity induced by $AFB_1$ or B(a)P was increased over 20% by 46 kinds and 2 kinds, respectively, and 8 medicinal plants (Chrysanthemum indicum, Cinnamomum cassia, Cyperus rotundus, Morus bombycis, Patrinia scabiosaefolia, Petasites japonicus, Polygonum multiflorium, Thyja orientalis) increased significantly the mutagenicity of both mutagens. However the 8 plants themself did not show the mutagenicity in SOS Chromotest with S-9 mix alone. This result suggests that the above 8 plants may have the co-mutagenic activities. In two bacterial mutation system, SOS Chromotest and Ames test, the mutagenic or antimutagenic activities of some medicinal plants wire similar except Ostricum koreanum, Eugenia caryophyllata and Scutellaria baicalensis.

• KDI Journal of Economic Policy
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• v.32 no.2
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• pp.144-170
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• 2010

This paper considers the effect of various types of procurement auction system on competition focusing on the rate of successful bidding. We analyze the number of bidders and the rate of successful bids using online procurement data of the Public Procurement Service. The average number of bidders is 301 and the average rate of successful bids is 87.42% while the weighted average rate is 75.13%. These numbers show that there is quite strong competition among bidders and the rate is lower as the expected price is higher. When we analyze the data of price procurement auction, the rate is also shown to be lower as the expected price is higher. Furthermore, the rate decreases as the number of bidders increases which naturally makes the competition stronger. Meanwhile, the analysis finds that the inclusion of the onsite bidding, the PQ(Pre-Qualification) result, or major-10 winning companies cannot explain the rate much in our data. In case of turnkey-alternative, the average rate of successful bidding for 484 cases record 90.20%. The average is 84.89% with 120 alternatives and 91.97% with 364 cases of turnkey. The reason why the rate of turnkey-alternative is lower than that of price procurement auction is the lack of competition as well as the systematic difference. By setting up a model, we are able to explain the difference in rate caused by the respective reason. When we suppose there are 3 bidders in case of price procurement auction for a project that exceeds 100 billion won, the rate is expected to be around 64%. This implies that difference of 26% is caused by the systemic difference and 3% by the lack of competition. Therefore, we conclude that the difference in rate between turnkey-alternative and price procurement auction is caused mainly by the systemic difference. In case of PPP(Public Private Partnership) projects, among 154 projects in total, only 40% has more than 2 bidders that compete. The average number of bidders is 1.88 which is less than 2, and the average rate of successful bids is 90%. In sum, under the price procurement auction, there is strong competition which is reflected by the rate of successful bids. However, there is room to decrease the rate by strengthening the competition under the turnkey-alternative. Also with PPP projects, we expect the rate can be steadily reduced with revived competition among bidders.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.53-65
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• 2001

Purpose : To improve the local control of patients with nasopharyngeal cancer, we have implemented 3-D conformal radiotherapy and forward intensity modulated radiation therapy (IMRT) to used of compensating filters. Three dimension conformal radiotherapy with intensity modulation is a new modality for cancer treatments. We designed 3-D treatment planning with 3-D RTP (radiation treatment planning system) and evaluation dose distribution with tumor control probability (TCP) and normal tissue complication probability (NTCP). Material and Methods : We have developed a treatment plan consisting four intensity modulated photon fields that are delivered through the compensating tilters and block transmission for critical organs. We get a full size CT imaging including head and neck as 3 mm slices, and delineating PTV (planning target volume) and surrounding critical organs, and reconstructed 3D imaging on the computer windows. In the planning stage, the planner specifies the number of beams and their directions including non-coplanar, and the prescribed doses for the target volume and the permissible dose of normal organs and the overlap regions. We designed compensating filter according to tissue deficit and PTV volume shape also dose weighting for each field to obtain adequate dose distribution, and shielding blocks weighting for transmission. Therapeutic gains were evaluated by numerical equation of tumor control probability and normal tissue complication probability. The TCP and NTCP by DVH (dose volume histogram) were compared with the 3-D conformal radiotherapy and forward intensity modulated conformal radiotherapy by compensator and blocks weighting. Optimization for the weight distribution was peformed iteration with initial guess weight or the even weight distribution. The TCP and NTCP by DVH were compared with the 3-D conformal radiotherapy and intensitiy modulated conformal radiotherapy by compensator and blocks weighting. Results : Using a four field IMRT plan, we have customized dose distribution to conform and deliver sufficient dose to the PTV. In addition, in the overlap regions between the PTV and the normal organs (spinal cord, salivary grand, pituitary, optic nerves), the dose is kept within the tolerance of the respective organs. We evaluated to obtain sufficient TCP value and acceptable NTCP using compensating filters. Quality assurance checks show acceptable agreement between the planned and the implemented MLC(multi-leaf collimator). Conclusion : IMRT provides a powerful and efficient solution for complex planning problems where the surrounding normal tissues place severe constraints on the prescription dose. The intensity modulated fields can be efficaciously and accurately delivered using compensating filters.