• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.27-32
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• 2010

This study is to investigate and compare domestic hazardous toys with harmful substances with foreign toys so that we can find out management criteria for in cognitive infants. Actually, commercially used toys have been collected and tested to find out more effective management standard. it is tried to produce evaluation criteria of environmentally harmful substance but variety of product is needed for overcoming actual barrier due to lot of difficulty huge cost, time, objectiveness. Therefore, This study does not cover all the above. Establishment of evaluation criteria for product harmfulness made by Government or Local government should be continued to improve. Foreign reference material for toy product in Europe, USA, Japan have been investigated and domestic product have been collected and tested for containing heavy metals, formaldehyde, phthalate in the study. All the test have been made in accordance with KSM ISO 2124 to measure heavy metal transfer into body. Toy product used for the study have been purchased in the real market and some of them contains harmful elements with over standard. Post management system such as RAPEX to control periodically should be established for plastic toy with low quality product.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.63-70
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• 1997

It has been observed that local increase in melanin synthesis or uneven distribution can cause local hyperpigmintation or spot. Pigmentary disorders are caused by various factors, including inflammation, imbalance of hormones, and genetic disorder. Recently the harmfulness of Ultraviolet radiation is increasing due to destruction of ozone layer. Excessive exposure to UV radiation caused post-inflammatory pigmentation. Most women want to avoid uneven skin pigmentation. To satisfy this desire many cosmetic companies have been developing melanogenesis inhibitors and finding promising active agents for use in cosmetic preparations for skin whitening. In cosmetic preparations, many inhibitors such as kojic acid, arbutin, ascorbic acid, and licorice extracts6 have been used as whitening purpose. Plant extracts having an inhibitory effect on melanin formation may be a good choice for cosmetic purpose because of their relatively lower side effects. Therefore, we screened 285 plant extracts for their inhibitory activity in tyrosinase. Of the plant extracts, ramulus mori extracts showed potent tyrosinase inhibition activity. We also identified the active compound in the extract.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.41-46
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• 2013

The cladoceran Daphniamagna has been used as an aquatic test species in aquatic toxicology. To evaluate the aquatic toxicity of leachate from concrete, the immobilization of D. magna was observed after treatment of various concentrations of leachate specimens. Reliabilities of the culture condition and the experimental protocol for acute toxicity test were successfully achieved from the standard toxicity test. The leachates were prepared from the mixture of Ordinary Portland Cement (OPC) and pozzolanic admixtures, Pulverised fuel ash (PFA), Ground granulated blast furnace slag (GGBS) and GGBS containing loess. Acute toxicity test showed 100% immobilization of D. magna for OPC or PFA. The leachates from OPC or PFA had high pH 10 to 12. However, GGBS and GGBS containing loess showed less toxicity according to the concentrations. Especially, immobilization was not observed at the concentrations below 12.5% of GGBS containing loess. Also the range of pH for these specimens was 8 to 9. This suggested that the use of loess as the admixture in concrete may be useful to reduce eco-toxicity of leachates from concrete. This our study provided the harmfulness of the alkali leaching from concrete in aquatic environment and the usefulness of D. magna to evaluate the toxicity of leachates from concrete.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.762-765
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• 2008

Shotcrete is NATM technique after tunnel excavation as major tunnel support for ground stability, curtail of execution period and reduction of execution expenses instead of general lining method. It is trend using constantly shotcrete lining. This high-strength shotcrete is require to use as constantly shotcrete lining. This brought out the solution of environmental pollution and harmfulness about human. Accordingly, in this study Specimens of strength measurement was made to develop shotcrete possible to develop in early materials with Cement Mineral Accelerator as NATM method construction. It's compared with existing shotcrete material, Unconfined Compression test, flexural strength test were experimented. The fish poison test was experimented to evaluate an influence of environment. On results of test, Unconfined Compressive Strength and flexural strength was equivalent with 28-day strength of existing material. On results of fish poison evaluation research subject material was founded environmentally friendly for existing shotcrete.

• Journal of Information Display
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• v.7 no.4
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• pp.13-16
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• 2006

II-$III_{2}-(S,Se)_{4}$ structured of phosphor have been used at various fields because they have high luminescent efficiency and broad emission band. Among these phosphors, europium doped $BaGa_{2}S_{4}$ was prepared by solid-state method. We investigated the possibility of applying [ ] due to emissive property of UV region. Also, general sulfide phosphors were synthesized by using injurious $H_{2}S$ $CS_{2}$ gas. However, this study prepared $BaGa_{2}S_{4}:Eu^{2+}$ phosphor is addition to excess sulfur under 5% $H_{2}$/95% $N_{2}$ reduction atmosphere. So, this process could involved large scale synthesis because of non-harmfulness and simple process. The photo-luminescence efficiency of the prepared $BaGa_{2}S_{4}:Eu^{2+}$ phosphor increased by 20% compared with commercial $BaGa_{2}S_{4}:Eu^{2+}$ phosphor. From this, we could conclude that the prepared $BaGa_{2}S_{4}:Eu^{2+}$ could be applied to green phosphor for white LED of three wavelengths.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1096-1099
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• 2006

$II-III_2-(S,Se)_4$ structured of phosphor have been used at various field because those have high luminescent efficiency and broad emission band. Among these phosphors, europium doped $BaGa_2S_4$ was prepared by solid-state method and we try to look into an application possibility due to an emissive property of UV region. Also, general sulfide phosphors were synthesized by using injurious $H_2S\;CS_2$ gas. However, this study prepared $BaGa_2S_4:Eu^{2+}$ phosphor is addition to excess sulfur under 5% $H_2/95%\;N_2$ reduction atmosphere. So, this process could large scale synthesis because of non-harmfulness and simple process. The photo-luminescence efficiency of the prepared $BaGa_2S_4:Eu^{2+}$ phosphor increased 20% than commercial $SrGa_2S_4:Eu^{2+}$ phosphor. The prepared $BaGa_2S_4:Eu^{2+}$ could apply to green phosphor for white LED of three wavelengths.

• Korean Journal of Health Education and Promotion
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• v.7 no.1
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• pp.72-82
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• 1990

The actual condition of drug abuse by some Juveniles in our country and effects of some elements on their drug abusing were observed providing basic materials for health education to juveniles to contribute to the health improvement of them and the reduction of the harmfulness of drug abuse. 1035 third school year students of some senior high schools in Seoul were subjected to the questionnaire survey. The results could be summarized as follows : 1. Among the twelve kinds of drug involved in the study, alcohol (72.0%), cigarette (44.2%), stimulants (23.9%), analgesics (7.9%) appeard abused in the order named. 2. As for the motives of using antitussives, 30.1% of students answered because of curiosity, then 28.8%, in order to get a calm condition, and then 16.4%, to get along with friends. 3. As the result from seeing how much each drug abuser is contact with his family, frends, school, social surroundings and himself, every abuser appeared having higher degree of discontentment with family, school, society and himself excepting friends. 4. And when analyzed the relationship between their misconducting and drug-abusing, a close relationship was shown : mere abusers among misconduct-experienced students, and more misconduct-experienced students among abusers.

• Journal of Korean Medicine for Obesity Research
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• v.7 no.1
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• pp.23-29
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• 2007

Background : Mahuang (Ephedra sinica) has been used widely to treat respiratory disease in traditional medicine for over thousands years. Mahuang preparations contain approximately $0.75{\sim}1%$ ephedrine alkaloids. Recently in North America, the Eephedra alkaloids has aroused a controversy due to its adverse effects in those using whole extracts as "dietary supplements" for weight loss or athletic performance enhancement. Objective : To discuss the need for clinical practice guidelines on the use of Mahuang. Results and Conclusion : It is widely assumed that Mahuang is one of the useful medicines and is safe for human body. Most of scientific literatures support that the safety of Mahuang prescription in common dosage. However, it has been claimed that there were some warnings and apprehensions about the harmfulness of Mahuang as dietary supplements. This article does not negate the fact that it is necessary to pay more attention for use of Mahuang in clinical situations. We assert that the establishment of clinical practice guideline on the use of Mahuang, which is based on scientific materials and consensus, is required in traditional medicine.

• Journal of Korean Academy of Nursing
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• v.27 no.2
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• pp.315-328
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• 1997

The purpose of this study was to explore the process of smoking behavior of college women with a history of smoking. The subject were 48 female students selected by theoretical sampling from a womens' university in Korea. The data were collected by in-depth interviews using audiotape recordings done over a period of seven months. The data were analyzed simultaneously by a constant comparative method in which new data were continuously coded into categories and properties according to strauss and corbin's methodology. Analysis of the data resulted in identification of 15 categories representing 34 concepts. The results of this study were as follows : 1. Smoking in college women is caused by either curiosity or antagonism toward male smokers 2. The meaning(phenomena) of smoking behavior in college women is justifiable or regretable 3. Smoking occurs in connection with eating, during period of psychological conflict or as an habitual practice 4. Smoking behavior is related to the perception of harmfulness to health, influence of others and the accessability of cigarettes. 5. College women experinced a change in their state of health, emotional relaxation, change in their social relationships It is suggested that the results of this study may contribute to the development of strategies for the purpose of decreasing smoking behavior among female college students.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.293-300
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• 2014

This paper proposes a novel pattern recognition approach based on the radial basis function (RBF) neural network for identifying insulation defects of high-voltage electrical apparatus arising from partial discharge (PD). Pattern recognition of PD is used for identifying defects causing the PD, such as internal discharge, external discharge, corona, etc. This information is vital for estimating the harmfulness of the discharge in the insulation. Since an insulation defect, such as one resulting from PD, would have a corresponding particular pattern, pattern recognition of PD is significant means to discriminate insulation conditions of high-voltage electrical apparatus. To verify the proposed approach, experiments were conducted to demonstrate the field-test PD pattern recognition of cast resin current transformer (CRCT) models. These tests used artificial defects created in order to produce the common PD activities of CRCTs by using feature vectors of field-test PD patterns. The significant features are extracted by using nonlinear principal component analysis (NLPCA) method. The experimental data are found to be in close agreement with the recognized data. The test results show that the proposed approach is efficient and reliable.