• Nuclear Engineering and Technology
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• 제40권4호
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• pp.269-276
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• 2008

Operational license of WWER-440/213 units at Paks NPP, Hungary is limited to the design lifetime of 30 years. Prolongation by additional 20 years of the operational lifetime is feasible. Moreover, enhancement of the reactor thermal power by 8% will increase both the net power output and the competitiveness of the plant. Paks NPP is a pioneer considering the power up-rate and preparation of long-term operation of WWER-440/213 design. Systematic preparatory work for long-term operation of Paks NPP has been started in 2000. A regulatory framework and a comprehensive engineering practice have been developed. According to the authors view, creation of a gapless engineering system via consequent application of best practices, and feed-back of experiences together with proper consideration of WWER-440/V213 features are the decisive elements of ensuring the safety of long-term operation. That systematic engineering approach is in the focus of recent paper. Key elements of justification and measures for ensuring the safety of long-term operation of Paks NPP WWER-440/213 units are identified and discussed. These are the assessment of plant condition and review of adequacy of ageing management programmes, also the review, validation and reconstitution of time limited ageing analyses as core tasks of licence renewal.

• 동남아시아연구
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• 제20권3호
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• pp.147-182
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• 2010

The purpose of this study is to examine the population changes in the nine Southeast Asian countries, including Cambodia, Lao People's Democratic Republic, Philippine, Indonesia, Malaysia, Myanmar, Singapore, Vietnam, and Thailand. According to the demographic transition theory which described the transition from high birth and death rates to low birth and death rates, the demographic changes in less developed countries, including the Southeast Asian countries, follow the general pattern of the population changes that the Western countries had experienced. However, this theory does not consider the fact that the demographic behaviors such as fertility and mortality tend to be ethnocentric (or particular). Therefore, I examine in this paper both the generality and particularity of the population changes in the Southeast Asia . The analytic results are consistent with my assumptions. Every country in the Southeast Asia will soon reach the third phrase of the demographic transition and meet population ageing process. However, the timings arriving at the third phrase can differ. Singapore which is the most developed country had firstly passed through the demographic transition and the highest level of population ageing. Cambodia and Lao People's Democratic Republic, the least developed countries, will lastly arrive at the third phrase and the ageing society. In addition, among the three countries which had experienced war or civil war, only Cambodia had experienced babyboom.

• 분석과학
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• 제26권3호
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• pp.190-198
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• 2013

호박은 오래전부터 장식품, 공예품, 부장품 등으로 사용되어 매장문화재 형태로 발굴되고 있다. 발굴 당시 호박은 풍화가 많이 진행되어 표면의 균열, 박락 등이 관찰된다. 풍화에 따른 호박의 성분 변화를 파악하는 것은 보존상태를 진단하고, 적절한 보존방법을 적용하는데 있어 매우 중요하다. 본 연구에서는 열분해/GC/MS로 호박의 열분해 산물을 분석하여 호박을 구성하는 성분을 찾고자 하였다. 또한, 열과 산소가 있는 조건에서 60일 동안 인공열화하여 호박의 열분해 산물의 구성비가 변화하는 것을 관찰하였다. 실험결과 호박의 주요 열분해 산물로 abietic acid가 검출되었고, monoterpene류, alkene류, aromatic hydrocarbon류가 검출되었다. 주요한 23개의 성분에 대해 열화에 따른 상대적인 면적비를 비교하여 열화에 따른 경향성을 파악하였다. 주성분인 abietic acid는 산소와 열이 있는 조건에서 급격하게 감소하였지만, 열만 있는 조건에서는 변화가 크지 않은 것으로 보아 산소가 호박의 열화에 중요한 역할을 하는 것으로 판단된다. 실제 풍화된 호박 원석의 표면에 대해 열화실험 결과를 적용하여 열화상태를 파악하는 시도도 하였다.

• 한국시스템다이내믹스연구
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• 제15권1호
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• pp.75-96
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• 2014

This research primarily aims at analyzing major crises originating from marginalizing population, especially in counties. In addition, based on the system dynamics approaches, it pays attention to divulging causal loop structure which has been rather strengthened by diverse interactions among key variables. Judging from simulation works, even though Korea is exposed to unprecedented aging trends over decades, its counter response seems inadequate and insufficient, mostly dismissing a series of impact embedded in the aging dynamics. This research statistically confirms that demographic marginalization trends have already begun in the villages within Eup and Myon counties. Furthermore, this research pinpoints out the fact that it would be almost impossible for majority of villages within Eup and Myon counties to escape from going out of existence in the course of time, as they tend to be entrapped vicious cycle of marginalization or extinction.

• Elastomers and Composites
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• 제17권1호
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• pp.13-21
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• 1982

The purpose of this dissertation is to compare bound andtioxidant, MHPPD with the ordinary one, IPPD, when high polymers are used like NR and SBR. The effect of rubber bound antioxidant and ordinary antioxidant on the Mooney scorch time has been studied by means of the Mooney viscometer. The ageing properties of vulcanizates containing rubber-bound antioxidant and ordinary antioxidant have been studied in terms of hardness, tensile strength and elongation. The results of the Mooney scorch time and ageing properties are as follows: When MHPPD was mixed with NR or SBR compounds, the Mooney scorch time was faster than the IPPD compounds. Also the ageing properties of the vulcanizates containing MHPPD were much superior to the IPPD compounds. Furthermore, the vulcanizates comporised of MHPPD have taken andvantage of and resistance in the ozone test.

• 한국세라믹학회지
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• 제27권5호
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• pp.577-582
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• 1990

The synthesis conditions of fibrous calcium sulfate hemihydrate were investigated by using phosphogypsum and calcium sulfate hemihydrate. The unstable organogel was deposited by adding methanol to the saturated solution with gypsum at ageing temperature, and it was crystallized to fibrous gypsum hemihydrate while methanol was removed by rapid filtrating. In case of using calcium sulfate hemihydrate, fibrous $\beta$-calcium sulfate hemihydrate was formed by adding methanol of 67% to saturated solution at 6$0^{\circ}C$ and ageing for 5 minutes and filtering with suction. Minor components in phosphogypsum did not affect the reaction.

• 한국식품영양과학회지
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• 제44권3호
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• pp.401-411
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• 2015

여주는 항당뇨, 항암, 항염증, 항바이러스 및 항산화 활성의 다양한 생리적 효능을 지니고 있다. 그러나 쓴맛으로 인해 여주를 이용한 식품 개발은 미비한 실정이다. 이에 본 연구에서는 여주를 이용하여 피클을 제조하고 숙성 기간 중 품질 특성과 항산화 활성을 살펴보았다. 숙성 4주 후에 피클의 pH, 염도, 가형성 고형분 및 환원당은 감소하였고 산도는 증가하였다. 한편 총 균수, 젖산균수 및 효모균수는 1주까지 빠르게 증가하다가 이후에는 약간 감소하였다. 여주 피클 숙성 중 수용성 phenolics는 증가하였고 이에 상응하여 항산화 활성도 증가하였다. 또한 여주 피클의 조단백질, 칼륨 및 인 함량은 여주 원료보다는 낮았으나 조지방 및 소금 함량은 높았다. 여주 피클 숙성 중 쓴맛과 향의 개선을 위하여 옥수수수염 추출물을 첨가하였는데 0.25% 옥수수수염 추출물 여주 피클이 관능적으로 가장 우수하였다.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.13-25
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• 2006

A new class of life distributions is studied. This class is defined based on comparing the residual life time to the whole life in the moment generating function order giving 'the new better than used in the moment generating function order ageing class $(NBU_{mgf})$'. Fundamental properties of this class are given including some closure properties and characterizations. Finally, we consider new results about comparisons of age and block replacement policies when the underlying distribution belongs to $NBU_{mgf}$ aging classes.

• International Journal of Reliability and Applications
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• 제5권4호
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• pp.155-162
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• 2004

A new class of life distributions is studied. This class is defined based on comparing the residual life to the whole life in the moment generating function order giving "the new better than used in the moment generating function order ageing class ($NBU_{mgf}$)". Some new results of this class are given including some closere properties and characterizations. Finally testing exponentially against the $NBU_{mgf}$ class is also addressed.

• International Journal of Reliability and Applications
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• 제8권2호
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• pp.175-182
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• 2007

In this note, some comments concerning the testing procedures for the problems of stochastic comparison, testing IFR and testing NBU ageing properties are presented showing that the tests proposed in Belzunce, Candel and Ruiz(1998) are cumbersome to calculate and do not have as good asymptotic Pittman efficacies as simpler others already in the literature. This is done via new presentations of the measures on which Belzunce et al. base their tests.