• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2002년도 추계학술발표논문집
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• pp.228-233
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• 2002

In this study, Life Cycle Assessment method has been carried out the Corrugated board box in considering environmental aspects by quantifying the environmental emission and assessing its environmental impact potential. The system boundary in this study is selected from cradle to gate stage(raw material acquisition, raw material production and product manufacturing) of the paper product. To evaluate the environmental impact potential, impact categories are divided into 8 categories. As a results, abiotic resource depletion of the impact categories has the largest contribution to the total impact potential as 31.02% of total, Next were continued ecotoxicity having a contribution of 27.17%. In the life cycle, environmental impacts from law material production stage were contributed largely as 80.78%.

• 청정기술
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• 제3권2호
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• pp.13-24
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• 1997

The present paper aims to give basic information to establish zero emission material cycle including the minimization of emissions from industrial production processes and the area in regional scale. Strategies and methodologies to analyze emissions from the production processes and our human activities and to reduce those emissions by refining and/or replacing the unit process with the alternatives are introduced as well. Quantitative evaluation and management systems of any raw materials and the production process are from vie points of treatment are essential. Estabiishment of a process networking for the recycle of discharged non-products materials by the intra-process, trans-process and the trans-industries are proposed. Procedures and priorities to formulate industrial and regional zero emission system are proposed as well.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2009년도 학술논문요약집
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• pp.73-73
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• 2009

There are many factors to evaluate nuclear fuel cycle such as safety, public acceptance, economics, etc.. Transparency, proliferation, environment issues, public acceptance and safety are essential to expansion of nuclear industry and proliferation resistance is one of key constraints in the deployment of advanced nuclear energy systems. Proliferation resistance is being considered as one of the most important factors in assessing advanced and innovative nuclear systems. IAEA defmes proliferation resistance as characteristics of nuclear energy system that impedes the diversion or undeclared production of nuclear material [1]. Barriers to proliferation is consist of intrinsic and extrinsic barriers(institutional measures). Intrinsic barriers are characterized in material barriers and technical barriers in general. Material barriers is intrinsic, or inherent, qualities of materials that reduce the inherent desirability or attractiveness of the material as an explosive. Isotopic, chemical, radiological, mass and bulk, detectability barriers are considered as material barriers attributes [2]. Proliferation resistance is examined for several nuclear fuel cycles based on previous study which is focused on the intrinsic barriers [3-4]. Pyroprocessing and DUPIC are considered as reprocessing technologies in Korea and the PWR direct disposal is considered. Comparative assessments of the proliferation attributes and merits of different fuel cycle systems will be performed and the optimal back-end fuel cycle and strategy will be proposed.

• 대한기계학회논문집A
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• 제26권9호
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• pp.1897-1904
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• 2002

Monotonic torsional and pure torsional low cycle fatigue(LCF) test with artificial degradation were performed on duplex stainless steel(CF8M). CF8M is used in pipes and valves in nuclear reactor coolant system. It was aged at 430$^{\circ}C$ for 3600hrs. Through the monotonic and LCF test, it is found that mechanical properties(i.e., yield strength, strain hardening exponent, strength coefficient etc.) increase and fatigue life(N$\sub$f/) decreases with degradation of material. The relationship between shear strain amplitude(${\gamma}$$\sub$a/)and N$\sub$f/ was proposed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.289-289
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• 2007

Spinel structured $LiMn_2O_4$ is more economic and environmental friendly to be used as commercial active material for secondary battery compared to Co-oxide material active material, but spinel structure of $LiMn_2O_4$ is unstable and its capacitance decreases with increase of cycle. Therefore, the purpose of our sturdy is to improve the stability of $LiMn_2O_4$ spinel structure and increase its capacitance by using substituents or dopants. $LiMn_2O_4$ powder was synthesized by charging substituents or dopants mole fractions, and temperatures. Crystal state, structure and specific surface area of the synthesized powder were measured and also characteried electrochemically by measuring its impedance, charge-discharge capacitance and etc.

• 복식문화연구
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• 제16권2호
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• pp.219-234
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• 2008

The purpose of this thesis is to conduct research on the degree of satisfaction (for both wearing and functioning) of cycle wear; to present the basic data to develop cycle wears which can lesson the trouble for human body and have an excellent feeling in wearing. To inquire the degree of satisfaction, the method of questionnaire was used for 100 peoples consisted of male cycling players. As the result of the satisfaction degree in wearing, it can be certain that the users are satisfied overall and yet they express the lowest satisfaction at material among material, design, color and function. When it comes to unsatisfactory factors of wearing cycle wear, the most unsatisfactory one is the poor function of clothing on the whole. As the result of the site suitability of cycle wear, we can find the problems on the girth of neck and armhole of the upper garment, and on the part from waist to hip length and the girth from thigh through knee to calf of lower garment. As the result of the motion suitability of cycle wears, we can acknowledge that there are problems on the part of neck, armpit, and abdomen of the upper garment rather than the lower one.

• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.385-389
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• 2003

There are four main components of the CMP process: polishing pad, slurry, elastic supporter, and pad conditioner. The polishing pad is an essential component to the reproducibility of polishing uniformity in CMP process. However, the polishing pad in recently using metal CMP raised the several points of high cost caused by the increase of cycle time and the many usage of slurry. It is necessary to develop the novel polishing pad which would lead the cost reduction by the higher pad life-cycle, minimized cycle time and lower slurry usage. The characteristics of polishing pad were studied on the effects of different sets of the Polishing pad, which can be applied to metal chemical mechanical polishing process for global planarization of multilevel interconnection structure. The main purpose of this experiment is cost reduction by the increase of pad life-time, the decrease of cycle time and the lower usage of slurry through the specific hard porous structured pad design. It is confirmed that the novel polishing pad made the slurry usage decrease to 60% as well as the pad life-time increase twice with the 25% improvement of removal rate. The polishing time could be decreased and it also helped the cycle time to diminish. It can be expected that this results will help both the process throughput and the device yield to be improved.

• International Journal of Precision Engineering and Manufacturing
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• 제3권2호
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• pp.78-86
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• 2002

In general, X-ray diffraction method detects the changes of crystal lattice under material surface using the angle of diffraction 2$\theta$. This technique which deals with in the presented paper can be applied to a behavior on the slipped band or the micro crack cause to material degradation. The relation between half-value breadth and cycle numbers shows three stages, which consist of rapid decrease in the initial cycle, slight decrease in the middle cycle, and then rapid decrease in the final cycle. The ratio of half-value breadth has a constant value on B/B$\_$0/ - N diagram under the loading condition except early part of fatigue life. The ratio of half-value breadth B/B$\_$0/ - log N$\_$f/ with respect to number of cycle to failure N$\_$f/ has linear behavior on B/B$\_$0/ - log N$\_$f/ diagram. Therefore, the evaluation of fatigue life by the average gradient has much less mean error than the estimation of fatigue life by log B/B$\_$0/ - log N/N$\_$f/ relation.

• 한국초등과학교육학회지:초등과학교육
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• 제29권4호
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• pp.567-575
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• 2010

The purpose of this study is to investigate the effectiveness of academic achievements, science process skill and scientific attitude. The subjects of this study were 68 fourth-grade elementary school students who were 33 students for the 5E learning cycle instruction and 35 students for traditional instruction. The control group was taught with traditional teaching method, while the experimental group was taught 'the change to the volume of material due to heat' unit of 4th grade with the developed learning cycle model. The results were as fellows: First, the learning cycle instruction is more effective for understanding of a concept related to the change to the volume of material due to heat. Second, the learning cycle model seems more effective for the expansion of both scientific inquiry ability and scientific attitude.

• 한국농공학회논문집
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• 제61권1호
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• pp.85-93
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• 2019

The objective of this study is to assess the environmental effect of the reclaimed land drainage method using oyster shell through the Life cycle $CO_2$ assessment, and to evaluate the applicability in South Korea. In this Study, the life cycle $CO_2$ emissions of oyster shell (OS) and crushed stone (CS, as avoided product) were assessed and compared. The Life Cycle Assessment method was used for quantitative evaluation of direct or indirect environmental effects of OS recycling. $CO_2$ was selected as the evaluation target material, and the scope of assessment includes the acquisition of materials, processing, transportation, construction phases. Compared to using CS, 77.0% of $CO_2$ emissions in acquisition and processing, 47.0% in transportation and 6.5% in construction phase were reduced, respectively by using of OS. The maximum transportation distance of OS was estimated according to transportation distance of CS. OS has environmental advantages than CS within about 26 - 101 km from the source. OS was found to be applicable to reclaimed lands up to 810 ha, 3,910 ha from Tongyeong and Yeosu, respectively. In addition, the amount of OS that could be used as drainage material for reclaimed land was much higher than annual OS production of South Korea. Therefore, it is considered that OS is sufficient to be used as drainage material for reclaimed land in South Korea.