• 한국환경보건학회지
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• 제14권1호
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• pp.73-86
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• 1988

In order to determine the content levels of trace metals in common salts, 64 bay salt samples were collected from three producing districts and 33 bay salt samples, 32 remade salt samples and 5 fine salt samples were collected from 7 major cities in Korea, from August to September 1987. These were analysed for content levels of Pb, Cd, Cu, Zn and Mn using Atomic Absorption Spectrophotometer. The results were as follows: 1. Lead contents in three type salts were N.D. - 1081.9 $\mu$g/kg and fourteen percent of the 114 samples exceeded the World Health Organization(WHO) criteria of 100$\mu$g/kg. Cadmium contents of samples were N.D.- 382C.5 $\mu$g/kg and five percent of the 114 samples were over the Spanish criteria of 500 $\mu$g/kg. Copper contents of samples were 8,9-214.9 $\mu$g/kg and there was not a sample over the World Health Organization(WHO) criteria of 500 $\mu$g/kg. Zinc contents ranged N.D. - 342.9 $\mu$g/kg and Manganese contents ranged N.D.- 8.31 mg/kg. 2. The comparison of heavy metal contents among the bay salts from three producing districts was significantly different in Pb, Cd and Cu contents. 3. The comparison of heavy metal contents between the bay salts and remade salts was not significantly different in Pb, Cd and Cu contents. 4. The contents of Pb, Cd, Zn and Mn in fine salts were much lower than those of bay salts and remade salts.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.48-54
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• 2020

Researchers recognized air pollution changes causing diseases and difficulties in living due to environmental pollution following various human activities, and have studied how to avoid fine dust harmful to the human respiratory system to be healthy. To this end, Arduino is used to equip fine dust level sensors in drones to measure the fine dust levels, visualize the measurements with LED indicator colors depending on the measurements to inform users of the danger of fine dust, and use the benefits of drones to specify dangerous fine dust zones and measure the fine dust levels. Users can see the changes depending on the fine dust levels in real time with the LED indicators. This will contributes to measuring fine dust levels easily in dangerous areas. Mission Planner (ArduPilot) is used to set up the GPS of drone, and store the data from the dust sensor as contents. This study aims to establish a method for improving the environment to measure fine dust levels with drones with LED indicators for fine dust, and reduce fine dust.

• 한국콘텐츠학회논문지
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• 제20권7호
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• pp.1-18
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• 2020

미세먼지는 전 세계 사망 원인 10대 중 하나이다. 세계 인구의 95% 이상이 그것에 의해 위험에 처해 있다. 본 연구는 적소 이론에서 미디어의 경쟁적 특성을 활용하여 위험 정보를 제공하는 다양한 유형의 미디어 사이의 상호 보완 관계를 정의, 효율적으로 제공하고 관리하기 위해 사용되는 방법을 탐구한다. 12일 동안 348명의 한국 대학생들로 구성된 설문조사는 미세먼지에 대한 소비자 인식, 미디어 이용, 미디어 이용 만족도 등 3가지 요인을 분석했다. 미디어 만족에 대한 응답 값은 적소 폭, 적소중복, 경쟁 우위를 도출하기 위해 방정식으로 대체되었다. 연구결과 미세먼지 예보 및 미세먼지 대응 지침 정보를 제공하기 위해 스마트폰 애플리케이션이 가장 효과적이었고, 스마트폰 애플리케이션이 미세먼지의 심각성과 발생원 등 추가 정보 제공에 제한돼 인터넷과 스마트폰 애플리케이션의 기능 확립이 필요한 것으로 조사됐다. 따라서 스마트폰 애플리케이션을 보완하는 위기전달 시스템을 개발해야 한다.

• 한국식품조리과학회지
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• 제14권5호
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• pp.584-588
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• 1998

Red pepper powders with variuos seed contents (0%, 10%, 20%) and particle sizes were stored at 0$^{\circ}C$, 20$^{\circ}C$, and 30$^{\circ}C$ for 90 days, and the changes in their characteristics were monitored. The initial moisture content was about 13%, and the powders were packed in 0.1 mm-thick polypropylene (PP) bags. Moisture content of each power remained constantly, so PP bags appeared to be effective to prevent moisture transmission. All the values of L＊, a＊ and b＊ were higher in fine particles than in coarse particles. Storage at 0$^{\circ}C$ did not change any color values, however, overall color values devreased apparently when stored at 30$^{\circ}C$ for 90 days. Capsanthin contents decreased gradually at all storage temperatures and more rapidly at higher temperature. The contents of capsaicinoids in fine particles (49∼59 mg%) were twic as much as those in coarse particles (15∼36 mg%), and they did not change throughout the storage.

• 한국지반공학회지:지반
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• 제12권5호
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• pp.137-154
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• 1996

화강토(화강암풍화토)의 세립자함유율에 따른 각종 띠형 보강재의 겉보기마찰계수의 변화를 알아보기 위하여 세립자함유율이 각각 7.28%, 19.58%, 35.86%인 3가지의 화강토 시료와 판형, 돌기형과 거친 무의형의 띠형 보강재를 대상으로 인발시험을 시행하였다. 인발시험결과 세립자함 유율이 증가하면 겉보기마찰계수는 감소하지만 세립자함유율이 35%인 화강토에서도 보강재 형상에 따라 보강토체 안정에 필요한 겉보기마찰계수를 얻을 수 있음이 확인되었다. 특히 돌기형 보강재는 세립자 함유율이 큰 화강토에서 매우 우수한 결과를 보였으며, 거친무늬형도 무늬깊이를 수정하면 35%의 세립자함유율의 화강토에 적용이 가능하다.

• 한국수자원학회논문집
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• 제33권1호
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• pp.133-142
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• 2000

본 연구에서는 불포화 투수계수를 측정하기 위하여 Klute(1965a)에 의하여 제안된 정적측정방법의 원리에 axis-translation의 기법을 적용하여 새로운 실험장치를 개발하였다. 이 실험장치는 모관흡수력(matric suction)의 증가에 따른 함수특성과 투수계수의 변화를 동시에 측정할 수 있도록 설계되었다. 실험에는 불포화 투수특성과 No.200체 통과 세립분의 상호관계를 규명하기 위하여 각각 세립함유량이 7.3%(인주), 19.6%(성환), 35.9%(구리)인 시료를 인주, 성환, 구리지역에서 채취하여 사용하였다. 실험결과에 의하면 불포화토의 투수계수와 체적함수는 시료의 밀도가 증가하는 경우 전체적으로 감소하였으며 모관흡수력이 증가함에 따라 점차 비선형적으로 감소하는 거동을 보였다. 또한 불포화토의 투구계수와 체적함수비는 상호 비선형거동을 보였다. 체적함수비와 투구계수를 직접 비교하는 방법으로 경험상수 A,B를 No.200체 통과 세립분의 함유량에 따라 결정하였으며, 경험상수 A, B를 이용하면 직접 흙의 함수특성곡선으로부터 불포화 투수계수를 추정할 수 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.7-11
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• 1996

The results of an experimental study on the mechanical properties of concrete utilizing crushed sand for construction materials are persented in this paper. As the results show, the workability, compressive strength and drying shrinkage were improved by propeer contents of replaced crushed sand. And the workability, compressive strength and drying shinkage were decreased by increasing very fine sand. Also, the suitable weight contents of replacing ratio of crushed sand in concrete using crushed sand were in range of about 30%. And the use of crushed sand containing very fine sand under the permitted limit by regulated KS F 2558 has not very much problems in concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.77-80
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• 2009

The purpose of the study was to examine engineering characteristics due to fine particle cement and gypsum contents to improve early strength of concrete substituted blast furnace slag powder. The results were as follows. Above all, For fluidity, generally all mixtures had lower fluidity than Plain mixture and was not satisfied target scope, but for mixture substituted the gypsum showed a little increasing trend. For air content, generally all mixtures compared to Plain mixture had decreasing tendency. However, all mixtures were satisfied target scope. For compressive strength, long-term strength was better than early strength according to ternary blast furnace slag contents was increased. For complex mixture was better than individual use of gypsum and fine particle cement.

• International Journal of Contents
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• 제17권4호
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• pp.35-45
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• 2021

In this study, we analyzed the factors that affect public awareness campaigns on social media platforms and developed an integrated model for measuring the persuasiveness of environmental social media campaigns. A survey questionnaire was created and distributed on Facebook with the goal of reaching individuals in their 20s and 40s in Vietnam, and 395 valid replies were gathered. The findings showed that the STOPS was reconfirmed as a suitable theoretical framework for analyzing the public's behaviour intention to conduct information related to the issue of fine dust, especially on social media. Furthermore, it also showed that social media efficacy has a moderating effect on the relationship between public's situational recognition and informational behaviour intention. This suggested that through social media platforms, personal characteristics play a vital part in developing effective environmental campaigns. Implications for both theory and practice were discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1458-1465
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• 2010

A lot of dredging and reclaming projects are recently under way in Korea for the efficient use of limiting land space. Saemanguem area is special case of reclaiming by dredged soil. In case of a confined disposal of dredged soils by a pump dredger, generally coarse grained soils are separated from fines with dropping at the near part of the pump dredger. This kind of seperation of fine contents could be a factor of liquefaction by earthquake. In Korea, recently, earthquakes with magnitude of 3.0 or higher are distinctively increasing in 1990. In this study, cyclic shear characterics of Saemanguem Dredged sand depending on fine content were analyzed. A series of undrained cyclic triaxial test with cyclic stress ratio ($\sigma_d/{2\sigma_{{\upsilon}c}}'$) were performed on both isotropic consolidated specimen and sand with fine contents of 0%, 5%, 15%, 30%, 40% under the effective vertical stress of 100kPa and 50% and 60%, 70% of relative density for fine content of 0%, respectively. In the test results, cyclic shear strength increased by increasing of cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) with increasing the relative density at the same number of cyclic under the effective confining pressure of 100kPa. It is almost highest the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10% at fine content of 15% between Cyclic stress ratio($\sigma_d/{2\sigma_{{\upsilon}c}}'$) value at cyclic number five and fine content. Number of cyclic is 30 under the effective vertical stress of 100kPa, 70% of relative density for fine content of 15%. when the cyclic stress ratio at each relative density was compared at cyclic number five, the double amplitude(DA) 1%, 3%, 5%, 7.5% and 10%, and the pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value were compared; under the relative density of 70% and the effective confining pressure of 100kPa. The pore-pressure ratio (${\Delta}u/{\sigma'}_c$) 0.95 value showed a similar trend to the double amplitude (DA) 5% line.