• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.119-125
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• 1999

This research has been studied in terms of investigating the reaction behavior of pyrite with a cyclone reactor. The Mathematical model has developed pyrite oxidation and lime sulfation in this reactor. The model assumes a chemical control shrinking core behavior for the pyrite and a fluid film control shrinking core behavior for the lime. The model was solved and characterized numerically. Experiments have been performed to study the influence of reaction parameters such as reactor temperatures, pyrite particle sizes, air flow rates, feeding rates, and mixing ratio of pyrite and lime. The oxidation and sulfation products were characterized chemically and physically.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.226-230
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• 2006

홍수피해잠재능(Potential Flood Damage: PFD)은 면 개념을 도입함으로써 치수단위구역의 치수특성 및 사회경제적인 가치를 함께 평가할 수 있도록 고안된 지수로 이미 여러 유역에서 시행되고 있는 유역종합 치수계획 사업에서 사용되고 있으나, 몇 가지 중요한 문제점이 꾸준히 제기되어 왔다. 본 연구에서는 우선 다음과 같은 이론적 문제점을 검토하였다. PFD는 처음 제안될 당시 (이하 기존 PFD) '잠재성'과 '위험성'라는 두 가지 요소가 곱해지는(multiplicative) 형태로 구성된 후 '위험성' 요소 안에 '가능성'과 '방어능력'이 더해지는 (additive) 형태를 취하고 있었다. 그러나 본 연구에서는 (이하 수정 PFD) '피해대상', '피해가능성', 그리고 '방어취약성'이 모두 곱해져야 이론적으로 타당함을 제시하였다. 기존 PFD는 '방어취약성'이 0의 값, 즉 홍수에 대한 완전방어를 의미하는 값에 가까워져도 PFD 값이 0에 수렴하지 않는 반면, 수정 PFD는 위의 경우 홍수 피해잠재능이 0에 수렴하는 것을 요소별 시나리오 모의를 통해서 확인할 수 있었다. 두 번째로 본 연구에서는 PFD를 이용하여 유역의 목표치수안전도 설정 방안을 제시하였다. PFD의 물리적인 의미가 무차원화 된 피해량 임을 전제로, 피해대상으로부터 목표방어율을 설정한 후 이에 해당하는 목표방어취약성을 계산하는 절차를 전개하였다. 추후 이 방법을 실제 자료에 적용하여 검증하는 연구가 이어져야 할 것이다.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.437-440
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• 1997

제어공학에서 흔히 표준 모델이라고 불리우는 플랜트 모델은 여러 부 시스템이 서로 결합되어있는 복잡한 시스템을 단순화시킨 모델이다. 이 모델은 수학적으로 간략하게 표시된다는 장점 때문에 다변수 시스템의 최적 제어에 많이 쓰이고 있다. 그러나 이 모델은 수학적인 전개에는 편리하지만 물리적으로 판이하게 다른 신호군 즉, 외란 및 측정 잡음과 기준 입력 신호를 하나의 신호군으로 처리하는 약점이 있다. 실제로 이 구조로는 입력 추종 문제를 자유롭게 처리할 수 없는 경우가 있다. 본 연구에서는 이러한 문제를 개선하기 위하여 외란 및 측정 잡음과 기준 입력을 분리하여 처리할 수 있는 2자유도 제어기 구조를 제시하였다. 제어기 형태는 위너-호프 제어기로 주파수 영역에서 다 변수 시스템에 대한 최적 설계를 가능하게 한다.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.110-114
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• 2001

In order to obtain the geological information of the shallow subsurface and the characteristics of resistivity curves to the lateral extent of the gold bearing gravel layer underlaid by a thick layer, electrical resistivity surveys had been carried out in the northern area of Takaoi village, Kalimantan, Indonesia from September 30th to October 27th in 1999. The Dipole-Dipole (Dp-Dp) resistivity survey was carried out with a electrode spacing of A=3m, 5m and electrode separation index n=10, and the vertical electrical sounding (VES) of the Schlumberger type was performed at 6 sites. The interpretation of the Dp-Dp data and VES curves by computer modeling indicates 5 classified layers as the horizontal structure. And the characteristics of VES curves shows us KH type.

• Journal of The Korean Association For Science Education
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• v.33 no.1
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• pp.132-143
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• 2013

The purpose of this study was to examine the nature of inquiry activities proposed in high school physics textbooks that were developed based on the 2009 science curriculum in Korea. The inquiry activities were analyzed using the notion of scientific practices introduced in the Science Education Framework (NRC, 2012). The results showed that the inquiry activities in the textbooks emphasized two of eight types of scientific practices including "Analyzing and interpreting data" and "Constructing explanations". In contrast, the activities required students to "ask questions" only once in a total of 291 science inquiry activities. The other types of scientific practices appeared less than 10%. Also found was that the types of scientific practices were not relevant to the way inquiry activities were used for textbook content. Implications for the curriculum and science teacher education were discussed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.9-20
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• 2012

The purpose of this research is to confirm how the determinant factors for shopping mall selection (proximity, parking facility, benefits, mutual interaction effects, physical environment, surroundings) affect attractiveness (image and appraisal) of the traditional markets and revisit intention and suggest strategic methods for revitalization of the traditional markets. Results of this research are drawn from a survey of customers who visit any of the twenty-two traditional markets in the Seoul area at least twice a week. Moreover, the theory is verified through the structural equation model analysis using the SPSS win 18.0 and AMOS 18 version statistics package. From the determinant factors of visiting traditional markets, parking facility, physical environment, and the surroundings were significant in image attractiveness; benefits, mutual interaction effects, and physical environment showed significant effects on appraisal attractiveness. Additionally, image attractiveness was not significantly influential in retention proneness while appraisal attractiveness was a key factor in deciding whether or not to revisit. Therefore, improvement in image is important but appraisal aspects like product reliability that customers can personally assess, are more essential for revitalization of traditional markets.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.34-42
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• 2003

In this paper, the image restoration process is interpreted as a backward diffusion process and the restored image is given as the solution of the backward diffusion equation (BDF). The ill-posedness of the backward diffusion if subdued by manipulating the exponentially increasing coefficients of the eigenfunctions. In manipulating the coefficients the spectral characteristics of an image is taken into account. The proposed scheme uses an exponentially decreasing function of the coefficients of the eigenfunctions beyond a certain threshold which is optimal with respect to the observation accuracy. The use of decreasing functions also improves the result compared with the constant bounded algorithm since it can include more low frequency components.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.131-131
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• 2010

원자의 여기 및 천이에 의한 플라즈마에서의 빛 방출은 일차적으로 여기를 위한 특정 문턱값 이상의 에너지 공급이 전제 된다. 진공 플라즈마에서 대부분의 에너지 전달 과정은 전자와의 물리적 충돌에 의해 일어나므로 충돌 여기의 결과 발생한 광신호 세기는 전자 에너지 분포에 대한 정보를 내포하고 있다. 전자는 입자들 간의 에너지 전달 매개가 되는 동시에 플라즈마 구성 입자 중 가장 가벼워 빠르게 주변 환경 변화에 응답하여 열평형을 이루므로 EEDF는 플라즈마의 미세한 변동까지도 보여줄 수 있는 인자가 된다. 플라즈마의 열평형 이동에 관한 정보를 광신호로부터 EEDF의 형태로 추출해내기 위해 BEB (Binary - Encounter - Bethe) 모델을 근거로 충돌 반응 단면적을 함수로 나타내어 신호를 분석하였다. EEDF의 꼴을 $f(E)=AEexp(-E^b)$의 임의의 형태로 두고 아르곤의 427nm, 763nm 두 빛의 세기 비를 BEB 모델을 적용하여 전개한 결과 b factor 의 값을 구할 수 있었다. b factor 가 1인 경우는 Maxwellian, 2인 경우는 압력이 높은 조건에서 잦은 충돌에 의한 에너지 손실 때문에 고에너지 전자군이 현격하게 감소된 Druyvesteyn 분포를 의미하므로 광신호에 모델을 적용하여 얻은 b factor의 변화는 EEDF의 형태 자체의 변화가 감지되었음을 보여준다. 실제로 13.56MHz - 1kW ICP 장치에서 아르곤 플라즈마를 발생시켰을 때, 압력이 낮아 Maxwellian 분포가 예상되는 10mTorr 조건에서는 b=1.13, Druyvesteyn 분포에 가까워지는 100mTorr 조건에서는 b=1.502 로 관측되었다.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.3
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• pp.379-397
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• 2009

The purpose of this study is to analyze the development and features of the abridged DDC (Dewey Decimal Classification), one of the main factors for DDC's success. For the study, a comparison table including the publication years and the physical features has been presented based on the general relationship between the full edited DDC and the abridged DDC. In addition, the contents and features have been analyzed from the first to the latest (14th) edition. Lastly, the time of introduction of four supplementary tables used in the abridged DDC and its development have been investigated.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.23-45
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• 2012

From 1990s the Ministry of Education and KERIS have developed nationwide academic resource sharing and service system based on universities, and have contributed to bridge the gap of information and to facilitate resource sharing between universities. Meanwhile, in Japan which starts 15 years earlier than us, the Ministry of Education and NII built nationwide academic resource sharing and service system with starting on the project of university holding resource sharing and until now have shown similar aspect of development like us. But lately, since information environment has been changing rapidly, Japan try to find new paradigm which goes around electronic resources management substitute for physical resources and open access based academic communication, institutional repository which disseminate university's research output to the outside world. This study compare academic resource sharing and service system between Japan and Korea and try to suggest for Korean academic resource sharing and service system development. In Korea, firstly we should try to replacing published resources management system to electronic resources', secondly, reorganizing oversea's resource sharing and service system, thirdly, reactivating institutional repository toward open access, finally, unification of distracted driving force.