• Nuclear Engineering and Technology
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• v.23 no.2
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• pp.165-173
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• 1991

The recycle of PWR spent fuels in a CANDU reactor, so called the tandem fuel cycle is Investigated in this study. This scheme of utilizing Pm spent fuels will ease the shortage of spent fuel storage capacity as well as will improve the use of uranium resources. The minimum modification to the design of present CANDU reactor is seeked in the recycle. Nine different fuel types are considered in this work and are classified into two categories： refabrication and reconfiguration For refabrication, PWR spent fuels are processed and refabricated into the present 37 rod lattice structure of fuel bundle, and for reconfiguration, meanwhile, spent fuels are simply disassembled and rods are cut to fit into the present grid configuration of fuel bundle without refabrication. For each fuel option, the neutronics calculation of lattice was conducted to evaluate the allowable burnup and power distribution. The fuel cycle cost of each option was also computed to assess the economic justification. The result show that most tandem fuel cycle options considered in this study are technically feasible as well as economically viable.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.528-537
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• 1996

Qualify changes of microwave-reheated cooked rice aseptic-packaged with different lid materials and oxygen absorbers were determined during storage at $20^{\circ}C,\;30^{\circ}C$ and $40^{\circ}C$. Springiness cohesiveness and adhesiveness increased as storage temperature increased, while gumminess and hardness decreased. Lid materials oxygen absorbers, and storage temperatures showed no significant effect on the textural properties of cooked rice after microwave reheating. Degree of gelatinization was increased as storage temperature increased and was restored after microwave reheating. Scanning electron micrograph showed that the surface of cooked rice became rough and hollowed after microwave reheating for 1.5 min, indicating starch was regelatinized, while there was no difference with respect to lid materials. Photomicrographs of the cross-section of aseptic-Packaged cooked rice showed that a compact and solid structure increased and retrogradation occured in starch as storage temperature decreased, while a compact and solid structure was decreased and starch was regelatinized after microwave reheating.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.77-83
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• 2010

음식물류 자원화 사업은 버려진 음식물 폐기물을 재가공하여 이를 자원으로 활용하는 사업으로 현재 정부와 민간, 그리고 지자체에서 적극적으로 추진하고 있는 사업이다. 그러나 음식물류 자원화 시설의 운영성과와 효율성은 제각각이며, 이에 대한 정확한 분석이 이루어지지 않고 있다. 이에 본 연구에서는 음식물 자원화 사업의 효율적이고 효과적인 수행에 필요한 기초자료를 제공하기 위하여 음식물 자원화 사업에 대하여 이론적으로 정리하고, 음식물 자원화 사업의 현황을 살펴보고자 한다. 이를 통하여 향후 음식물 자원화 사업의 추진에 필요한 음식물 자원화 시설의 효율성 평가를 위한 방법론을 제시하고자 한다.

• Proceedings of the Safety Management and Science Conference
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• 2010.04a
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• pp.161-166
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• 2010

항공물류 분야의 개선을 위해 공항에서 연구와 투자를 통하여 공항 선진화를 이루고 있고, 우리나라도 지속적으로 증가하는 항공물류 분야의 개선이 필요하다고 인식하고 개선을 위한 방안을 연구하고 있지만, 항공물류 전반에 걸쳐 통합적인 개선이 이루어지지 않고 개별적이거나 부분적인 시스템 개선으로 중복 투자와 비효율성의 문제가 발생하고 있다. 본 논문에서는 이러한 문제점들을 해결하기 위해 현행 항공물류 프로세스를 수 출입으로 구분하여 분석하였고, 시스템 통합 사례들을 검토하여 프로세스 상에서 발생하는 문서들을 분석하였다. 이중 인터페이스 대상 문서를 선정하고 문서의 데이터 내용과 형식을 정의하였다. 정의한 데이터의 형식을 대상 문서에 코드로 적용시키고 시뮬레이션을 통하여 데이터 저장량을 비교 분석하였다. 이를 통해 항공물류 이해관계자간의 정보 교환이 용이해지고 동일한 정보를 재생성하거나 재가공하는 비효율성을 감소시킬 것으로 기대된다.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.1-13
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• 1998

In this paper, it has been discussed on the relation between the anatomical features of woods and the penetration of methyl methacrylate monomer system into major Korean tree species, especially the Pinus koraiensis, Larix leptolepis, Quercus mongolica and Tilia amurensis. 1. There was some differences in penetration of polymers among different tree species, but generally the penetration of ring porous woods seems to be larger than that of diffuse porous woods and it was very difficult to penetrate to Larix leptolepis, especially to the that of heart wood. 2. The penetration on transeverse surface was relatively easy but radial and tangential impregnation were somewhat hard and differences between them were negligible. 3. The penetration of sapwood was larger than that of heartwood and its differences varied according to the existence of tyloses or contents in vessel. 4. Generally the polymer penetration of earlywood was larger than that of latewood in ring porous woods, but on the contrary, penetration of earlywood was small than that of latewood on diffuse porous woods. 5. Vessel diameter of wood had nearly no relation to polymers penetration. This seems to come from the reason that effective vessel diameter varies with the existence of tyloses or contents in vessel. 6. The penetration of ray tracheids was larger than that of ray parenchyma cells in softwoods, but penetration of hardwood rays seems to be small in comparison with softwood ray parenchyma cells. 7. Specific gravity and annual ring width had no relation to the penetration of polymer.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.3
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• pp.263-278
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• 2022

This paper contains experimental study for the development and performance of TBM backfill material with thixotropic properties. The LW backfill material is widely applied to fill the cavity on the back side of the shield TBM excavation, but has disadvantages such as settlement caused by strength reduction, material separation by groundwater, and reduced plasticity. In this paper, laboratory tests and a model test were conducted to assess the performance of inorganic thixotropic backfill material proposed to improve these problems. The results of laboratory tests show that 1 hr-uniaxial compressive strength of ITB was 12 times higher than LW, and the rate of bleeding of 20 hr was 8.3 times lower, and the result of flow table test was more than 27 times higher. This result indicated that the inorganic thixotropic backfill material has superior properties to LW backfill in terms of strength reduction, material separation, and thixotropy. In the model experiment, a model injection device tester was manufactured and the injection performance and filling rate were verified. When material was injected in the water, it was visually checked whether material separation occurred, and it was confirmed that the filling rate was 96% or more. Comparison results with the test of LW and ITB materials was concluded that ITB can reduce the material separation by groundwater and the occurrence of tunnel cavity.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.253-259
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• 2012

Disposal of high amount of coal combustion by-products, such as fly ash and bottom ash, is of a great concern to the country, due to the huge treatment cost and land requirement. On the other hand, those coal-ash wastes are considered to have desirable characteristics that may improve physical, chemical, and biological properties of soils. Especially, compared with fly ash, bottom ash has a larger particle size, porous surface area, and usable amount of micronutrients. In the present study, we examined bottom as a soil amendment for mitigating $CO_2$ emission and enhancing carbon sequestration in soils fertilized with organic matter (hairy vetch, green barely, and oil cake fertilizer). Through laboratory incubation, $CO_2$ released from the soil was quantitatively and periodically monitored with an enforced-aeration and high-temperature respirometer. We observed that amendment of bottom ash led to a marked reduction in $CO_2$ emission rate and cumulative amount of $CO_2$ released, which was generally proportional to the amount of bottom ash applied. We also found that the temporal patterns of $CO_2$ emission and C sequestration effects were partially dependent on the relative of proportion labile carbon and C/N ratio of the organic matter. Our results strongly suggest that amendment of bottom ash has potential benefits for fixing labile carbon as more stable soil organic matter, unless the bottom ash contains toxic levels of heavy metals or other contaminants.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.153-162
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• 2015

A descriptive research is studied to identify the physical factors affecting to cognitive function among elderly residents over 65 years old in a community. The data were collected from 352 participants as part of a health-related survey by home visits in Seoul in 2010-2012. Their cognitive function was measured using the Korean form of Hasegawa Dementia Scale(HDS-K) and the collected data were analyzed by using t-test, ANOVA, and multiple regression analysis. From the analysis, the prevalence rate of cognitive impairment was 13.6%. Elderly residents in a community showed different cognition levels by the status of age, change of weight, change of BMI, walking and flexibility exercise. Especially, the lowest cognition level was found in the normal BMI group with decreased BMI change by over 3. The factors influencing on cognition level of the elderly with normal BMI were age, change of weight, change of BMI, and walking exercise. The variance indicated 12.2% as their cognition level. Therefore, for preventing the cognitive impairment of the elderly that were rapidly decreased of BMI, we need the program to manage their nutrition and walking exercise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.480-486
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• 2020

The National Registered Cultural Heritage no. 377, 'The Eclectic-style House in Daeheung-dong, Daejeon', was relocated in 2013, even though it was privately owned. The relocation of National Registered Cultural Heritage through an urban redevelopment project is rare because the restriction of the preservation of a cultural asset is relatively tolerated. For the sake of profit in a redevelopment project, a privately owned Registered Cultural Heritage is likely to be demolished with no laws to prevent it. This study researched the history of the heritage and the procedure of the relocation process. Based on the research, the study intends to clarify the relationship between the economic and legislative conditions with the result of the National Registered Cultural Heritage relocation in general. The failure of the successful relocation of the National Registered Cultural Heritage in redevelopment projects is caused mainly by a change of ownership, which is generally from personal to anonymous associations. Based on the condition, this study maintained the Cultural Heritage's redefinition as a public asset and proposed phased amendments in each major procedure of a redevelopment project for the successful preservation and reuse of National Registered Cultural Heritage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.197-207
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• 2020

The purpose of this study was to identify the predictors of death anxiety among community-dwelling elderly cancer survivors in Korea. This study was a descriptive correlation study with 216 elderly cancer survivors who live in the jurisdiction of community health centers in Chugbuk province. Data of this study were collected from February 27 to March 15 2019 by a structured questionnaire. The data were analyzed using independent t-test, one-way ANOVA, Pearson's correlation coefficient, and hierarchical multiple regression. In the results, the mean score of death anxiety was 2.47±0.39 out of 4.0, while that of ego integrity was 2.60±0.29, depression 6.35±4.0, and awareness of a good death 2.97±0.35. Based on the hierarchical multiple regression analysis, subjects' awareness of a good death had the greatest impact on death anxiety (β = 0.255, p < .001), followed by depression (β = 0.185, p = .020) and religion (no= 1; β= 0.148, p = .021). These factors explained 16.4% of death anxiety (F=8.04, p<.001). Therefore, the results of this study are expected to be utilized as basic data for developing an intervention program that will be designed to reduce the death anxiety in elderly cancer survivors.