• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.907-910
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• 2008

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biochemical reaction originated from sulfur-oxidizing bacteria. To prevent biochemical corrosion of the sewage concrete, antibiotics which inhibit growth of sulfur-oxidizing bacteria have to be developed and applied necessarily. In this study, we are going to introduce technology which biochemical corrosion of sewage facilities concrete could be controlled effectively by antibiosis of antimicrobial concrete

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.85.2-85.2
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• 2010

국립과천과학관은 2008년 11월에 개관하였고, 천체관측소에는 직경 1-m 반사망원경과 4k CCD카메라, UBVRI Filter system이 설치되어있다. 국립과천과학관 관측시스템의 시야는 28.16각분이고, CCD카메라는 Cryogenic 방식의 냉각으로 $-110^{\circ}C$ 정도로 냉각할 수 있다. 또한 CCD카메라는 4개의 증폭기(Amplifier)를 이용하여 읽기 시간을 줄일 수 있도록 설계되어 있다. 이 연구는 국립과천과학관 관측시스템을 과학적인 목적으로 사용하기 위해 기기적인 특성을 먼저 알아보기 위함이며 진행 중에 있다. 현재까지 관측한 자료를 바탕으로 시간에 따른 영점영상의 변화, 노출시간에 따른 암전류 영상의 변화, 증폭기 에 따른 영점영상의 차이 등을 분석하였다.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.66-71
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• 1998

This study was investigated to evaluate worker exposures to organic solvents by type of print industry. Results were as follows; 1. Workers were exposed to mixture of toluene, isopropyl alcohol(IPA), methyl ethyl ketone(MEK), n-hexane, ethylacetate(EA), acetone. The components of high exposure solvents were toluene, IPA and MEK. 2. Considering additive effects of the compounds, exposure indices(Em) were calculated. The Mean of exposure indices were 1.79 for Gravere, 0.41 for Screen and 0.14 for Opset workplace. The workers of Gravere workplace were estimated to overexpose for solvents. 3. The highest overexposed solvent was toluene for a single component. The rate of overexposed level for toluene was 7.41% for some print workplace and for mixed solvent was 1.85％. 4. Local exhaust systems were inappropriate and respiratory protective devices were not supplied to the workers. 5. Sound level was over 90dB(A) in Opset print workplace and some measures should be performed to get down the sound level.

• Defense and Technology
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• no.10 s.176
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• pp.8-9
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• 1993

록히드사가 제작한 마하 3의 첩보 비행기 SR-71 Blackbird가 1990년에 첩보 비행 임무를 종료하게 되었을 때, 많은 항공 전문가들은 미 공군이 무언가를 숨기고 있다고 생각하였다 지금까지 나타난 여러가지 징후들을 종합해 보면 SR-71의 후속비행기로서 마하 6의 속도를 가진 첩보 비행기가 존재한다는 심증이 굳어지고 있다 다른 첩보 비행기를 운용할 계획도 없이 SR-71만 운용 중지키로 하고 더 이상 이 문제에 대한 언급이 없는데 대해, 대부분의 군사 전문가들은 미 공군이 세계에서 가장 빠르고 고공으로 비행하는 비행기를 운용 중지하면서 그 후속 대안없이 손을 뗀다는 것과, 그럴 경우 정보수집임무의 많은 것을 포기해야한다는 점에 강한 의문을 소개한다 미 정부 관리들은 이런 종류의 비행기를 보유하고 있지 않다고 부인하면서 위성을 이용해 첩보 비행기가 수행하던 임무를 충분히 수행할 수 있다고 말하며, 또한 록히드사에서도 SR-71 후속 첩보기를 개발하는데 참여한 바 없다고 부인하고 있으나, 그동안 수집된 자료를 종합해보면 미 정부가 이 비밀 첩보기의 존재를 자의로 밝히던지 또는 타의에 의해 밝혀지던지 곧 노출될 것으로 보인다

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.69-70
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• 2012

추사파 중에서 항행하는 선박은 여러 유형의 전복 사고 위험에 노출되어 있다. 추사파 중에서의 선체 거동을 규명하기 위해서는 먼저 추사파 중에서 항행하는 선박이 만나는 파도 즉, 만남파의 특성 규명이 필요하다. 이 만남파는 선박의 속도와 관련이 있으며, 본 연구에서는 해양파의 에너지 스펙트럼을 이용하여 만남파의 특성을 검토, 고찰하였다. 그 결과, 추사파 중에서 항행하는 선박이 만나는 파도는 실제 해양파보다 비교적 규칙적인 대파고가 된다는 것을 수치 계산 예를 통해서 규명하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.259-260
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• 2019

장애인은 비장애인보다 극한 상황에 쉽게 노출될 수 있어 큰 주의가 필요하다. 본 논문에서는 OpenCV 라이브러리를 기반으로한 손동작 인식 시스템을 제안한다. 장애인을 비롯한 몸이 불편한 사람들이 간단한 동작만으로 집 안의 모듈을 제어할 수 있도록 시스템을 구현하였다. OpenCV 라이브러리를 기반으로 카메라 촬영을 통해 손동작을 인식하여 물체를 제어하는 시스템을 설계하였다.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.1-11
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• 2023

Skin sanitizers are effective in killing or removing pathogenic microbial contaminants from the skin of food handlers, and the progressive growth of consumer interest in personal hygiene tends to drive product diversification. This review covers the advances in the application of efficacy tests for hand sanitizers to suggest future perspectives to establish an assessment system that is optimized to each product type (gel, liquid, and wipes). Previous research on the in vivo simulative test of actual consumer use has adopted diverse experimental conditions regardless of the product type. This highlights the importance of establishing optimal test protocols specialized for the compositional characteristics of sanitizers through the comparative analysis of test methods. Although the operational conditions of the mechanical actions associated with wiping can affect the efficacy of the removal and/or the inactivation of target microorganisms from the skin's surface, currently there is a lack of standardized use patterns for the exposure of hand sanitizing wipes to skin. Thus, major determinants affecting the results from each step of the overall assessment procedures [pre-treatment - exposure of sanitizers - microbial recovery] should be identified to modify current protocols and develop novel test methods. The ex vivo test, designed to overcome the limited reproducibility of in vivo human trials, is also expected to replicate the environment for the contact of sanitizers targeting skin microorganisms. Recent progress in the area of skin microbiome research revealed distinct microbial characteristics and distribution patterns after the application of sanitizers on hands to establish the test methods with the perspectives on the antimicrobial effects at the community level. The future perspectives presented in this study on the improvement of efficacy test methods for hand sanitizers can also contribute to public health and food safety through the commercialization of effective sanitizer products.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.19-26
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• 2009

The microwave exposure device for microwave breast cancer detection consists of RF transceiver and several antennas. The microwave information of object acquired from the microwave exposure device can be calculated permittivity and conductivity by using the inverse scattered analysis. In this paper, we have developed the software for detecting breast cancers based on microwave tomography, by which users not only can check out the existence of breast cancers through the permittivity and conductivity information analysis of the object's internal, but also can analysis easily information for distribution of breast cancers. The developed software provides the function for visualizing the captured permittivity and conductivity information as 2D or 3D color images on which users can easily detect the existence of breast cancers. For more detailed analysis of tomography images, the proposed software also has provided the functions for displaying their cutting profiles as well as position and size information of special area in them.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.893-896
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• 2008

As this study is to test fundamental properties of cement mortars using in Metakaolin. Recently concern is increasing for concrete durability because of an increase in the concrete structure exposed to bad environments. In the event that mineral admixture Added, microstructure will be fined, so durability can be good. Also, the study for new admixture is progressing expect that admixture widely used, for example, silica fume, fly-ash, and slag, etc. Therefore this study is making an experiment on fundamental properties of diversities sample curing at water, sea water, 10% sodium sulfate solution, and magnesium sulfate solution, to compare using for metakaolin with silica fume and fly-ash.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.1-8
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• 2007

The influence of individual size, sediment, gain size, water temperature, salinity and air exposure on burrowing rate was investigated in order to obtain the basic biological data on applying shellfish farm for a sustainable production of ark shell, Scapharca broughtonii (Schrenk). The burrowing rate on individual size 300 minutes after starting the experiment was the highest in the shell length $16.3\;{\pm}\;1.2\;mm$, 97.7%. The highest burrowing rates were 97.0% in $12.8\;{\pm}\;0.8\;mm$, 96.7% in $9.2\;{\pm}\;1.0\;mm$, and 96.3% in $5.9\;{\pm}\;0.7\;mm$. The clams over 6 mm of shell length had burrowing ability and the burrowing rate was not related to the shell size. The burrowing rate depending on the kind of grain at the bottom after 300 minutes was the highest, 98.3%, in the mixture of sand and silt with a ratio of 75:25. The rates were 98% in silt (100%), 97.3% in mixture sand and silt with a ratio of 50:50, 97.3% in sand and silt ratio of 25:75, and 86.3% in sand (100%) in this specific order. On grain size of the soil in the seafloor, the burrowing rates after 300 minutes was at its highest in the group of sand in pore size 1 mm with 85.0%, and the $12\;{\mu}m$ to 1 mm in the grain size was fitted to burrowing of artificial seed. In the case of water temperature, the burrowing rates were at its highest after 300 minutes. In $30^{\circ}C$ group, the rate was 96.7% and in $25^{\circ}C$ and $20^{\circ}C$, 90.0%. The rates decreased as the water temperature decreased below $15^{\circ}C$. The burrowing rates on salinity were the highest in 30 psu with 93.3% and at 15 psu and below, there was no noticeable change in the burrowing rate. On air exposure, the burrowing rates after 300 minutes were the highest in 1 hour with 93.3%, and remarkably decreased as air exposure time is longer after 12 hours of air exposure.