• 천문학회보
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• 제36권2호
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• pp.93.1-93.1
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• 2011

Radio wave from a compact radio source such as a quasar are scattered by irregularities of electron density. The scattered waves interfere with each other as they propagate to the Earth producing diffraction patterns on the ground. This phenomenon is called interplanetary scintillation (IPS). The IPS pattern contains the information of solar wind velocities and density fluctuations passing across a line-of-sight (LOS) from an observer to a radio source. The IPS is a useful tool which allows us to measure the solar wind in three dimensional space inaccessible to in situ observations. Although the IPS measurement is an integral of solar wind velocities and density fluctuations along the LOS, which causes degradation of accuracy, we have succeeded to develop computer assisted tomography (CAT) analysis to remove the effect of LOS integration. These techniques greatly improved the accuracy of determinations of solar wind velocity structures. In this talk we present our IPS observation system and long-term variation of global solar wind structures from 1980-2009, then we focus on recent peculiar solar wind properties.

• Environmental Engineering Research
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• 제15권1호
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• pp.49-56
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• 2010

Based on a survey of citizens and data analysis on the environmental status of the Miyun Reservoir watershed, China, the environmental awareness of citizens residing in the watershed and the impacting factors are discussed. The contingent valuation method was used to evaluate the willingness of villagers to pay (WTP) for abatement of the rural domestic pollution and to assess the intensity level of the villagers' desire for improving environmental conditions in the Miyun Reservoir watershed. It was found that rural watershed residents had a fundamental cognitive understanding of the pollution status and protection measures of the Miyun Reservoir. However, based on the survey, local residents had only a small interest in their participation to improve the environmental status of the reservoir, despite their general attitude to protect the reservoir being very positive. Gender and family income were closely associated with the overall attitudes of the population. Public media are the most preferable means for conveying knowledge of environmental protection to people living in the watershed. Increasing the educational level, along with income, are the best ways to enhance the desire of the villagers to improve the environmental quality and management.

• 한국물환경학회지
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• 제23권4호
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• pp.504-511
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• 2007

Built-out issue of copper processing appearing recently in the Paldang watershed is a critical problem to deteriorate the basic framework of national water management policy as well as to be simply a copper-related problem. Up to now, Korea government has invested hard and relevant upstream areas have been victimized readily in a variety of field to comply its goal of 'Safe Water Supply'. Because of the reason, the desirable water quality level of the Paldang watershed has been maintained regardless of its dense population. Paldang drinking water management policy is based on residents' understanding which is considered as a 'social capital'. The issue raised in the aspect of water quality management policy should be reviewed on the basis of the 'social capital' concept. One regarding semiconductor industry as a potential industry to export many products in 10 years insists that the industry not be a simple private business but be a prominent part for national competitiveness. There is no doubt about this opinion. However, a nation should support environmental right-to-life of its people prior to any other tasks. In other words, it is really risky to give up people's right due to economic benefits. Therefore, it should not happen to trade 'life', the dignity of man, with national competitiveness which is likely to be preferred in these days. In addition, coherent policy not to destroy 'social capital' promoting Paldang drinking water resource management policy should be maintained.

• Tuberculosis and Respiratory Diseases
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• 제82권2호
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• pp.94-101
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• 2019

Nontuberculous mycobacteria (NTM) are ubiquitous organisms that are generally found not only in the natural environment but also in the human engineered environment, including water, soil, and dust. These organisms can form biofilms and can be readily aerosolized because they are hydrophobic owing to the presence of the lipid-rich outer membrane. Aerosolization and subsequent inhalation were the major route of NTM lung disease. Water distribution systems and household plumbing are ideal habit for NTM and the main transmission route from natural water to household. NTM have been isolated from drinking water, faucets, pipelines, and water tanks. Studies that used genotyping have shown that NTM isolates from patients are identical to those in the environment, that is, from shower water, showerheads, tap water, and gardening soil. Humans are likely to be exposed to NTM in their homes through simple and daily activities, such as drinking, showering, or gardening. In addition to environmental factors, host factors play an important role in the development of NTM lung disease. The incidence and prevalence of NTM lung disease are increasing worldwide, and this disease is rapidly becoming a major public health problem. NTM lung disease is associated with substantially impaired quality of life, increased morbidity and mortality, and high medical costs. A more comprehensive understanding of the infection source and epidemiology of NTM is essential for the development of new strategies that can prevent and control NTM infection.

• 지구물리와물리탐사
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• 제24권2호
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• pp.45-52
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• 2021

소프트웨어 기술 발달에 따라 점점 더 많은 과학자와 공학자들이 연구를 위해 컴퓨터 소프트웨어와 프로그래밍 도구들을 사용하고 있다. 소프트웨어를 이용한 연구에서는 환경 설정, 재현성 및 소스 코드 손실과 같은 문제들이 발생할 수 있다. 이 해설에서는 리눅스 컨테이너와 버전 관리 시스템을 사용하여 이러한 문제를 방지하는 방법에 대해 조사하였다. 연구 프로젝트 단위로 클라우드 저장소를 통해 코드를 관리하고 리눅스 컨테이너에 연구 환경을 구축하면 위의 문제들을 방지하고 협동 연구를 더 쉽게 만들 수 있다. 리눅스 컨테이너 사용 경험이 없는 연구자들을 위해 컨테이너 생성과 실행에 필요한 스크립트를 포함한 연구 프로젝트 템플릿 저장소를 공개하였다.

• 설비공학논문집
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• 제25권4호
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• pp.180-186
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• 2013

An electric vehicle is an environment-friendly automobile which does not emit any tailpipe pollutant. In a conventional vehicle with an internal combustion engine, the internal cabin of the vehicle is usually heated using waste heat from the engine. However, for an electric vehicle, an alternative solution for heating is required because it does not have a combustion engine. Recently, a heat pump system which is widely used for residential heating due to its higher efficiency has been studied for its use as a heating system in electric vehicles. In this study, a heat pump system utilizing air source and waste heat source from electric devices was investigated experimentally. The performance of the heat pump system was measured by varying the mass flow rate ratio. The experimental results show that the heating capacity and COP in the dual heat source heat pump were increased by 20.9% and 8.6%, respectively, from those of the air-source heat pump.

• 정보보호학회논문지
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• 제27권4호
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• pp.721-729
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• 2017

악성코드에 대한 빠른 대응을 위해서는 악성코드에 대한 효율적인 분석이 필요하다. 그 중 하나로, 오픈 소스 함수들과 같이 안전한 것으로 확인된 부분을 분석 대상에서 제외하여 방대한 분석 대상을 줄이는 방법이 도움이 될 수 있다. 본 논문은 여러 오픈소스의 동적 링크 라이브러리 파일을 윈도우 환경에서 생성하여 오픈소스의 함수 정보들을 버전별, 컴파일러별로 시그니처 정보를 추출하고 비교하여 변경이 의심스러운 함수를 찾을 수 있는 자동화 도구를 제시한다. 또한 해당 도구는 비교에 사용된 정보들을 DB에 저장, 추후에 사용할 수 있어 분석 시간 오버헤드를 줄일 수 있다.

• 조명전기설비학회논문지
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• 제25권4호
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• pp.16-23
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• 2011

Since the first lighting light source was invented, lighting has turned into superior-quality lighting considering the amenity of occupants, and the characteristics of a light source has developed rapidly. So this research confirmed the lighting performance of a dimmer control system and an ON-OFF control system via the existing light source, and analyzed the basic lighting environment of Permanent Supplementary Artificial Lighting of Interiors(PSALI) through the physical comparison and evaluation of a LED lamp substituted for a fluorescent lamp used in a dimmer control system, showing that the lighting physical quantity characteristics of an ON-OFF control system and a dimmer control system are similar to each other and that they are effective in terms of energy saving. Besides, it was shown that introducing a LED light source to a dimmer control system improves lighting environments and largely reduces energy consumption.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.200.2-200.2
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• 2011

This study was carried out in order to estimate the greenhouse performance for Ground filtration water source heat pump which was installed for supplying the heat to the paprika greenhouse in Jinju city. Experimental area of Greenhouse was $3,300m^2$, For keeping the heat from greenhouse, single plastic covering and double thermal screen was installed. With considering all of greenhouse insulation condition and designed heatng temperature, heating capacity for experimental greenhouse was calculated as 320,000kcal/hr. Coefficient of performance(COP) of Ground filtration water source heat pump was gauged and greenhouse heating performance was tested from Febuary 1 to Febuary 28 in 2011. The result showed that COP of heat pump was in the range of 3.7~4.7 and COP of heating system was in the range of 3.0~3.5. The vaule of COP was very high and the temperature inside greenhouse was well corresponded to the setting temperature of greenhouse environment controlling system. lots of Ground filtration water made the the number of well fewer and the expense for installing heating system cheaper than that of geothermal system used custmarily. and this system went beyond the limitation of intaking amount of groundwater in normal Groundwater source heat pump.

• The Journal of the Acoustical Society of Korea
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• 제20권4E호
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• pp.52-60
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• 2001

This paper describes real time implementation of subband sound localization system on a floating-point DSP TI TMS320C31. The system determines two dimensional location of an active speaker in a closed room environment with real noise presents. The system consists of an two microphone array connected to TI DSP hosted by PC. The implemented sound localization algorithm is Subband CPSP which is an improved version of traditional CPSP (Cross-Power Spectrum Phase) method. The algorithm first split the input speech signal into arbitrary number of subband using subband filter banks and calculate the CPSP in each subband. It then averages out the CPSP results on each subband and compute a source location estimate. The proposed algorithm has an advantage over CPSP such that it minimize the overall estimation error in source location by limiting the specific band dominant noise to that subband. As a result, it makes possible to set up a robust real time sound localization system. For real time simulation, the input speech is captured using two microphone and digitized by the DSP at sampling rate 8192 hz, 16 bit/sample. The source location is then estimated at once per second to satisfy real-time computational constraints. The performance of the proposed system is confirmed by several real time simulation of the speech at a distance of 1m, 2m, 3m with various speech source locations and it shows over 5% accuracy improvement for the source location estimation.