• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.281-288
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• 2002

Crab shell 충진 칼럼을 이용한 수중 중금속의 연속적 제거에 있어서 다른 흡착제 (CER, GAC, Zeolite)와 비교 실험을 통하여 crab shell의 중금속 제거능을 알아보았다. 수중 $Pb^2+/{2+}$ 의 column을 이용한 연속적제거에 있어서 미세침전부분이 외부로 배출됨으로 칼럼 외부에 여과시스템의 도입함으로써 중금속 제거능을 높일 수 있을 것으로 판단된다. 중금속의 연속적 제거에 있어서 CER의 1,000 BVs까지의 전체 제거량은 0.35mmol/g, GAC는 0.17mmo1/g, zeolite는 0.16 mmol/g으로 나타났고 crab shell에 의한 중금속 제거량은 0.61 mmol/g으로 다른 흡착제보다 높은 제거효율을 보였다. 수중 중금속의 연속적 제거에 있어서 여러 흡착제의 제거 순서는 crab shell > CER > GAC > zeolite 로 나타났다. Crab shell의 경우는 파과점이 2,000 BVs에서 나타나므로 일반적인 폐수처리의 화학적 처리 후 잔존하는 저농도의 중금속을 제거를 위해 crab shell 충진 칼럼이 유용 할 것으로 판단된다. Crab shell의 재사용 가능성을 알아보기 위하여 crab shell을 이용한 중금속 제거공정에서 연속적인 중금속제거와 탈착과정을 통하여 보았을 때 1회에서 $Pb^2+/{2+}$제거된 량은 0.71 mmol/g 제거되었고 2회에서는 0.27 mmol/g, 3회에서는 0.02 mmol/g으로 급격하게 crab shell의 제거능이 떨어지는 것을 관찰 할 수 있다. 이는 crab shell이 재사용이 불가능 할 것으로 판단되나 다른 흡착제보다 월등한 제거효율을 보이므로 수중 중금속의 연속적 제거 흡착제 적합할 것으로 판단된다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.1-18
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• 1987

Prediction performances by Einstein's equation of diffusivity, Peskin's model, Three-Equation model, Four-Equation model and Algebraic Stress Model, have been compared by analyzing twophase (air-solid) turbulent jet flow. Turbulent kinetic energy equation of dispersed phase was solved to investigate effects of turbulent kinetic energy on turbulent diffusivity. Turbulent kinetic energy dissipation rate of particles has been considered by solving turbulent kinetic energy dissipation rate equation of dispesed phase and applying it to turbulent diffusivity of dispersed phase. Results show that turbulent diffusivity of dispersed phase can be expressed by turbulent kinetic energy ratio between phases and prediction of turbulent kinetic energy was improved by considering turbulent kinetic energy dissipation rate of dispersed phase for modelling turbulent diffusivity. This investigation also show that Algebraic Stress Model is the most promising method in analyzing gas-solid two phaes turbulent flow.

• Journal of Global Scholars of Marketing Science
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• v.8
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• pp.39-59
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• 2001

The production of the tea leaf is characteristic of the geographical distribution. The farmer of the Chonnam, Cheju, kyongnam has taken the their chance of the income crops in the tea leafs. The income crops has been developed the production system by the leaf producer. The consumer has improved the conditions of the life in search of the efficiency in the consumer system. Coping with the systems in the production and consumer, It requires consideration from the change and extension in the distribution systems. The distribution systems has gone through with the power of creation in the demand and supply.

• Archives of design research
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• v.15 no.4
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• pp.307-316
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• 2002

Metaphor thinking is a kind of intuitive thinking and plays a central role in design process. But there are not many researches on this topic because it happens in designer's mind during design problem solving. In this paper, we considered cognitive aspects of metaphorical thinking as they cropped up in the process of design concepts development. As a method of cognitive experiment we used a protocol analysis of the design review reports. At the end of this research we concluded that metaphorical thinking is engaged in restructuring of new frames and reconciliation of conflicting frames for the development of new design ideas and concepts. This role of metaphorical thinking makes the design thinking divergent and the design process creative.

• The KIPS Transactions:PartD
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• v.11D no.7 s.96
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• pp.1491-1498
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• 2004

Successful project planning relics on a good estimation of the manpower required to complete a project, together with the schedule options that may be available. Despite the extensive research done developing new and better models, existing software manpower estimation models are present only the total manpower or instantaneous manpower distribution according to the testing time for the software life-cycle. This paper suggests the manpower estimating models for software testing phase as well as testing process and debugging process in accordance with de-tected faults. This paper presents the polynomial model for effort based on testing and debugging faults. These models are verified by 5 different software project data sets with coefficient of determination and mean magnitude of relative error for adaptability of model.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.607-621
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• 1988

The paper describes the incorporation of an algebraic stress model(ASM) of turbulence in to a semi-elliptic solution procedure for the prediction of turbulent flow in passage around a 180.deg. square sectioned bend. The numerical results are obtained from a finite-volume discretization with applications of QUICK scheme and full find grid system without PSL approximation. Results show that the better agreements in velocity profiles with experimental data than those from k, $\varepsilon$ equation model with wall function and PSL are obtained. Predictions of Reynolds stresses also show good agreements with the experimental data.

• Journal of Korea Game Society
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• v.11 no.1
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• pp.159-168
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• 2011

Online game industry has achieved remarkable development not only in Korea, but also in the world with support from huge progress in information technology. By the way, there was calm period that top tier MMORPGs had held their ranks in oligopoly situation before Aion's appearance. At that time, NHNgames succeeded to penetrate into the market and settle down as a major player. In this context, this study will identify the factors of successful market entry strategy and draw helpful ideas by analyzing case of NHNgames which succeeded to enter the market of MMORPG through the basic strategic framework of Kalyanaram and Gurumurthy. This discussion will provide several implications for the solution of online game market penetration problem which might be never ended and for the way of industry's development.

• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.366-369
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• 2008

To evaluate the performance of a bipolar packed bed cell (BPBC) filled with granular aluminium, the experiments were carried out in two groups as batch and continuous processes. In a batch process, removal efficiency of total phosphate (T-P) was 88% in case of electrolytic treatment of phosphate solution, T-P 10 mg/L at 6 V during 3 h by BPBC filled with granular aluminium. In a continuous process, residual T-P concentration was about 2 mg/L in case of electrolytic treatment of phosphate solution, 10 mg/L at 6 V, HRT 3 h by BPBC filled with granular aluminium. Break-through point was observed after running for 120 h at hydraulic retention time (HRT) of 3 h.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.185-190
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• 2007

대용량의 자료가 생산됨에 따라 데이터를 효율적으로 저장, 관리, 이용할 수 있는 데이터 웨어하우스의 역할이 중요하게 되었고, 그에 따라 자료 처리 기법의 개발은 필수 과제가 되었다. 품질 평가와 오류 판단, 결측 보정의 자료 처리 과점은 자료의 신뢰도를 판단하고 활용도를 높일 수 있는 과정으로 매우 중요하다. 본 논문에서는 우리나라의 실제 교통상황을 반영하고 평가 기준의 오차를 줄이면서 더욱 간단 명료한 평가 계산식을 도입하여 효율적인 품질평가와 오류판단, 결측 보정의 자료 처리 기법을 제안한다. 또한 오류 판단 기준에 새로운 파라미터론 도입하여 교통 연구자의 요구 사항을 반영할 수 있게 하였다. 결측 보정 과정은 여러 기법을 연구하고 기존의 결측 보정 기법에 입력 변수를 추가하여 실제 대용량의 교통 자료에 적용하였다. 그리고 교통 자료가 저장되는 데이터베이스에 직접 접근하여 결측 보정과정을 수행하도록 PL/SQL로 구현하였으며, 이를 통해 교통 연구자에게 쉽고 다양한 방법으로 결측 보정을 수행하고 그 결과를 이용하여 다양한 교통 정보를 가공할 수 있는 환경을 제공하였다.

• Journal of The Korean Association For Science Education
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• v.23 no.1
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• pp.9-20
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• 2003

In this study, elementary school students' views about nature were searched. The participants were 18 students of fifth grade and sixth grade. Data were collected via semi-structured interviews involving a set of elicitation devices used to encourage students to talk about their views about nature, The results showed as follows; (1) Elementary school students had diverse views and common views about nature, (2) Their views about nature were affected by various factors, such as religion, aesthetical aspect, science, society, and so on. So when science educators construct science curriculum, they must consider these factors. (3) It is necessary to be concerned about the relations between science curriculum and others.