• Advances in concrete construction
• /
• 제1권1호
• /
• pp.85-102
• /
• 2013

Prior concrete strength distributions can be updated by using direct information from test results as well as by taking into account indirect information due to conformity control. Due to the filtering effect of conformity control, the distribution of the material property in the accepted inspected lots will have lower fraction defectives in comparison to the distribution of the entire production (before or without inspection). A methodology is presented to quantify this influence in a Bayesian framework based on prior knowledge with respect to the hyperparameters of concrete strength distributions. An algorithm is presented in order to update prior distributions through numerical integration, taking into account the operating characteristic of the applied conformity criteria, calculated based on Monte Carlo simulations. Different examples are given to derive suitable hyperparameters for incoming strength distributions of concrete offered for conformity assessment, using updated available prior information, maximum-likelihood estimators or a bootstrap procedure. Furthermore, the updating procedure based on direct as well as indirect information obtained by conformity assessment is illustrated and used to quantify the filtering effect of conformity criteria on concrete strength distributions in case of a specific set of conformity criteria.

• 한국안전학회지
• /
• 제27권1호
• /
• pp.63-69
• /
• 2012

Ready-mixed concrete(RMC) has been a major construction materials for infrastructures. However, RMC with poor quality is reported to be social issue since it directly user's safety and convenience. Because the properties of concrete as a construction material are greatly influenced by the variation of water content, to control water accurately is the most efficient method for the quality control in RMC industry. In this study, the automatic measurement technology of fine aggregate was developed by using the microwave moisture measurement. For the various conditions of fine aggregate such as moisture, temperature and pressure, the calibration curve of moisture measurement was obtained by using oven-dry method. From the infield and outfield test, it can be obtained that the accuracy of microwave moisture measurement is very high and the automatic system of microwave moisture measurement is very convenient and useful for quality control in RMC Industry.

• 산업경영시스템학회지
• /
• 제26권4호
• /
• pp.12-22
• /
• 2003

The purposes of this study are to investigate the conformity of Korean Standards(KS) according to agreement on WTO/TBT, and to propose systematic frameworks of preparation, adoption, and application for KS in our enterprises. Significant changes in this establishment, revision, and abrogation include the following divisions; i) statistics-vocabulary and symbols, ii) Shewhart control chart, iii) statistical interpretation of data, iv) sampling procedures for inspection by attributes, v) sequential sampling plans for inspection.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제32권1호
• /
• pp.12-25
• /
• 2016

Recently, research investment in the improvement of food safety as a food source and specializing of nutritional source of edible insects is being actively conducted. Cricket especially has been attracting considerable interest in entomophagy; however, research on the safety assessment of cricket is limited. This study investigated the effects of cricket ethanol extract when orally administrated in Sprague-Dawley rats. Here, we performed a 4 wk repeated oral dose toxicity test in Sprague-Dawley rats following the Organization for Economic Cooperation and Development test guidelines 407 under Good Laboratory Practice regulation. Rats were randomly allocated 4 groups: vehicle control, 250, 500, 1,000 mg/kg test groups and administrated based on body weight for 28 d. The animals were observed for mortalities and clinical signs, body weight changes, food and water consumption. At the end of treatment period, blood and urine were collected and analyzed. Subsequently, the animals were sacrificed and subjected to gross pathological examination and organ weight measurement. The organs were preserved for histopathological examination. The results showed that there were no systemic toxicological effects related with the cricket ethanol extract in the 4 wk oral repeated dose toxicity study. It is considered that NOAEL of cricket ethanol extract is greater than 1,000 mg/kg/d and there was no target organ detected.

• 산업경영시스템학회지
• /
• 제32권2호
• /
• pp.104-111
• /
• 2009

Recently, it is becoming the big issue internationally where the safety problem of the industrial product including the foodstuffs. The way is able to construct the trust of the consumer that the external specialized agency independently operating confirms what production process of the product keep a standard or a technical regulation. This is conformity assessment. In the many countries, agencies entrusted government authority do conformity assessment. Specially, 'certification' in one form of conformity assessment process is operating a certification system at the government and the non-government body in Korea. Also non-government certification is fixed by trusted system from consumer. He has to prepare a competitive power in liberalization time, so need the countermeasure urgently. This study purpose that develops strategy so as to activating of non-government certification system in gist of the origination called 'self-control.' I present activation strategies using SWOT/AHP analysis.

• 한국의류학회지
• /
• 제34권8호
• /
• pp.1341-1351
• /
• 2010

The Korean jean market has become increasingly competitive due to the increased imports of global brands. This study is to understand the purchase behaviors of Korean college students toward foreign brand jeans to help Korean jean brands enhance their competitive advantages over foreign brand jeans in the Korean market. Considering perceptions of Korean consumers toward foreign brands and traditional value changes, this study proposed a research model incorporating two extended behavioral intention (BI) models, Lee's modified BI model and Ajzen's theory of planned behavior. To test the research model, a total of 240 valid data sets were collected from college students in Busan, Korea. Structural and measurement models were estimated using LISREL 8.80. Because face saving failed to attain internal validity, the research model was revised to eliminate face saving. The findings indicated that perceived behavioral control had the strongest direct influence on purchase intentions of Korean college students for foreign brand jeans. Group conformity and subjective norm had non-significant direct impacts on purchase intention, whereas group conformity had an indirect impact on purchase intention through attitude. Based on the findings, theoretical and managerial implications were provided.

• Corrosion Science and Technology
• /
• 제12권3호
• /
• pp.149-157
• /
• 2013

In corrosion-sensitive areas of exsisting unpainted weathering steel bridges with closed box girder structures. there are some serious local corrosion problems because of rain water or dew water which can not be solved by exsisting maintenance methods. These problems must be controled technically because of bad. influence on the safety of bridge. This study is the first stage of developing the economic corrosion control manual for these local corrosion problems. Through the injection of tar sealant into the crevice of mock-up equipment, it was prooved that the corrosive sealant can be useful to corrosion control at crevice of corrosion sensitive area.

• Corrosion Science and Technology
• /
• 제12권4호
• /
• pp.191-197
• /
• 2013

This study is the second stage of developing the corrosion control technical manual about unpainted weathering steel bridge with closed box girder structures. This paper contains selection of corrosive sealant to apply into crevice of upper flange, injecting test of sealant at mock-up equipment with various condition, evaluation of experiment result. Through the experiment of injection of sealants into crevice of mock-up equipment, it is proved that the tar sealant injecting corrosion control method is useful to protect corrosion at box girder upper flange corroded by remaning rain water with calcium chloride.

• Toxicological Research
• /
• 제32권2호
• /
• pp.159-173
• /
• 2016

Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource.

• 한국콘텐츠학회논문지
• /
• 제14권4호
• /
• pp.445-455
• /
• 2014

본 연구에서는 개인 미디어로 청소년들이 늘 휴대하고 있는 스마트폰을 통한 성 관련 콘텐츠 이용에 영향을 미치는 요인을 인구사회학적 속성, 개인적 속성, 그리고 미디어 이용시간이나 미디어의 종류 등을 통해 분석하고자 했다. 연구결과, 스마트폰의 성 관련 콘텐츠 이용 정도에 영향을 미치는 요인은 남학생, 고등학생, 아버지의 학력이 고등학교 졸업 이하인 경우 통계적으로 유의미한 영향을 미쳤고, 자기통제성이 낮을수록, 또래동조와 차별접촉이 높을수록 스마트폰으로 성 관련 콘텐츠를 더 이용하는 것으로 나타났다. 스마트폰에서 성 관련 콘텐츠의 의도적 노출 정도에 영향을 미치는 요인에서도 남학생, 고등학생의 경우 통계적으로 유의미한 결과를 나타냈고, 자기통제성이 낮을수록, 차별접촉이 높을수록 스마트폰으로 성 관련 콘텐츠를 의도적으로 이용하는 것으로 나타났다. 음란물의 노출 뿐 만 아니라 다양한 수준의 성 관련 콘텐츠의 영향 요인에 대한 연구를 바탕으로 청소년이 많이 이용하는 미디어 채널을 통한 건강한 성 관련 메시지의 전달 방법 등을 강구하고, 미디어 교육 등 미디어의 긍정적인 활용 방안을 제시함으로써 미디어가 청소년의 바람직한 가치관 형성에 도움을 주는 좋은 의미의 수퍼피어(super-peer)의 역할을 할 수 있도록 계속적인 연구가 필요하다.