• Nuclear Engineering and Technology
• /
• 제49권4호
• /
• pp.734-743
• /
• 2017

In order to investigate the swelling behavior and fuel-cladding interaction mechanism of U-10Zr alloy metallic fuel at very low burnup, an irradiation experiment was concisely designed and conducted on the China Mianyang Research Reactor. Two types of irradiation samples were designed for studying free swelling without restraint and the fuel-cladding interaction mechanism. A new bonding material, namely, pure aluminum powder, was used to fill the gap between the fuel slug and sample shell for reducing thermal resistance and allowing the expansion of the fuel slug. In this paper, the concise irradiation rig design is introduced, and the neutronic and thermal-hydraulic analyses, which were carried out mainly using MCNP (Monte Carlo N-Particle) and FLUENT codes, are presented. Out-of-pile tests were conducted prior to irradiation to verify the manufacturing quality and hydraulic performance of the rig. Nondestructive postirradiation examinations using cold neutron radiography technology were conducted to check fuel cladding integrity and swelling behavior. The results of the preliminary examinations confirmed the safety and effectiveness of the design.

• Earthquakes and Structures
• /
• 제4권4호
• /
• pp.397-428
• /
• 2013

This paper examines whether the "effective period" of bilinear isolation systems, as defined invariably in most current design codes, expresses in reality the period of vibration that appears in the horizontal axis of the design response spectrum. Starting with the free vibration response, the study proceeds with a comprehensive parametric analysis of the forced vibration response of a wide collection of bilinear isolation systems subjected to pulse and seismic excitations. The study employs Fourier and Wavelet analysis together with a powerful time domain identification method for linear systems known as the Prediction Error Method. When the response history of the bilinear system exhibits a coherent oscillatory trace with a narrow frequency band as in the case of free vibration or forced vibration response from most pulselike excitations, the paper shows that the "effective period" = $T_{eff}$ of the bilinear isolation system is a dependable estimate of its vibration period; nevertheless, the period associated with the second slope of the bilinear system = $T_2$ is an even better approximation regardless the value of the dimensionless strength,$Q/(K_2u_y)=1/{\alpha}-1$, of the system. As the frequency content of the excitation widens and the intensity of the acceleration response history fluctuates more randomly, the paper reveals that the computed vibration period of the systems exhibits appreciably scattering from the computed mean value. This suggests that for several earthquake excitations the mild nonlinearities of the bilinear isolation system dominate the response and the expectation of the design codes to identify a "linear" vibration period has a marginal engineering merit.

• 인문언어
• /
• 제8집
• /
• pp.331-367
• /
• 2006

In this paper I attempted to investigate the matters related with the clarification of the close relationship between writing system and pronunciation. On the way of pursuing the research on the subject I found the fact that the same topic has been the main academic target in Korea. There have been some remarks about English alphabets and pronunciation. Nevertheless, the relation between alphabet codes and pronunciation tokens wasn't considered as the main key to master the English pronunciation correctly and completely. As the main target of this paper I argue that it is necessary to comprehend the connection. Then, we can recognize the significant role of alphabetic structure for understanding the gist of pronunciation exercise. This paper is classified into four parts. Each part consists of the material to affirm the fact that writing system should be the inevitable equivalent of sound system, and vice versa. In the first section I show that the development of the way of pronouncing English words is closely related with the endeavors of the scholars. While performing the survey of the studies about the alphabetic structure of the age many scholars found that the spelling construction was recorded without any common denominator. Thus, they not only sought to stage the bedrock for the standard written form of words but also to associate the alphabet letters with phonetic features. Secondly I mention the negative aspect of the 'only spelling based English pronunciation education' for the educational goal of 'Phonics methodology.' In this part I suggest the essentiality of phonemic properties with the phonetic prospect: phonemic awareness. Thirdly I refer to the standardization of the spelling system of English. As the realm of application of the language is extended toward the various professional areas such as commercial, scientific, and cultural spheres, it is quite natural to assume that the usage of the language will be transformed according to the areas in the world. Fourthly I introduce the first English-Korean grammar book with the section of 'the introduction to English pronunciation.' At the chapter the author explained the sound features of English based on the regulation of 'Scientific Alphabet' of U.S.A. In the transcribing system all the symbols were postulated on the basis of the English alphabet form instead of the separate phonetic signs of IPA.

• 대한조선학회논문집
• /
• 제34권3호
• /
• pp.53-60
• /
• 1997

일반적으로 선박 판부재의 좌굴강도에 대한 안전성 평가는 선체구조 설계단계에서 반드시 거쳐야 할 단계로 한 척의 배는 수많은 판부재로 구성되어 선박구조 전체에 대한 이론적이며 체계적인 시스템을 이용한 좌골강도평가의 정확도 및 효율성이 강조되고 있다. 그러나 현재의 판부재 좌굴강도를 평가하는 각 선급의 규정치가 많은 영향인자를 고려치 않고 있거나 함축척으로 고려하고 있기 때문에 경우에 따라서는 좌굴강도가 상당한 안전측의 값을 제시하는 등 실제 선급규정치의 사용에 제약을 주기도 한다. 따라서 본 연구에서는 면내인장력의 영향등 선급들의 좌굴 규정치뿐만이 아니라 면내인장력의 효과, 경계조건, 횡하중 및 잔류응력등을 고려하면서 손쉽게 좌굴평가를 수행할 수 있는 선진 좌굴평가시스템을 개발하였다. 이들 선진 좌굴평가시스템을 이용하면 선박판부재의 보다 정도 높고 효율적인 평가가 가능하리라 생각되며 앞으로 대중적인 사용을 위해 워크스테이션 외에도 개인용 컴퓨터에서의 시스템 구축을 계획하고 있다.

• 한국중재학회지:중재연구
• /
• 제25권4호
• /
• pp.77-95
• /
• 2015

CISG provides a uniform framework for contracts of sale of goods between parties whose places of business are in different States. In 2004 South Korea became the 63th State around world to adopt CISG. Starting next year CISG goes into effect as the law that governs the contracts for international sale of goods, in respect of which CISG displaces the existing domestic civil and commercial codes of Korea. By its provision Article 1(a), CISG applies directly between Contracting States without reference to private international law. As South Korea's biggest trade partners including China, the U.S. and Japan are also parties to CISG, the number of such direct applications continuously increases. Now it is estimated, though roughly, that CISG governs about two-thirds of Korea's import and export trade of goods. The private survey of the author shows that up to now in South Korea there are 39 court cases decided by the first instance courts, 29 cases by the appellate court and six cases by the Supreme Court of South Korea. In nearly all these cases, CISG applied directly. Furthermore, currently CISG is, in several respects, influencing upon the revision of Korean civil code which is designed to modernize it: The revised draft published in 2013 adopts the rules on the revocation of offers provided in articles 15 and 16, the rule on the termination of offers provided in article 17 and the rule on the time that an acceptance takes its effect provided in article 18 of CISG. More importantly, in accordance with the rules taken by CISG, the revision draft no longer requires the existence of fault or negligence on behalf of the breaching party in order for the aggrieved party to void the contract, and the revised draft denies the right of avoidance for trivial, not fundamental, breaches of contract.

• Journal of Radiation Protection and Research
• /
• 제9권1호
• /
• pp.33-42
• /
• 1984

핵분열(核分裂) 및 방사화생성물(放射化生成)物)에서 방출(放出)하는 여러가지 감마선들은 핵연료(核燃料)를 파괴(破壞)하지 않고도 추출(抽出)할 수 있는 많은 정보(情報)를 포함(包含)한다. 그러나 반도체(半導體) 검출기(檢出器)에서 얻은 복잡한 스펙트럼에서 이러한 정보를 추출(抽出)하기가 용역(容易)하지 않기 때문에 전산(電算)코드의 사용(使用)이 필요(必要)하게 된다. 본(本) 연구(硏究)에서는 그동안 국제적(國際的)으로 널리 보급(普及)되어 사용(使用)되는 감마선 분석(分析) 프로그램들의 장점(長點)을 취하여, 감마선은 물론 X-선(線)의 스펙트럼도 피팅 (fitting)하여 피이크의 중심과 면적을 정확(正確)히 계산(計算)할 수 있는 전산코드 CAERI를 개발(開發)하였다. CAERI는 FORTRAN으로 쓰여있고, 특히 고유복사선폭(固有輻射線幅)(natural line width) 을 무시할 수 없는 X-선(線)의 피이크 표현함수(表現函數)인 Voigt 함수(函數)에 대해서는, 다른 X-선(線) 분석(分析) 프로그램들이 사용(使用)한 간단한 근사식(近似式) 대신에, 더욱 정확(正確)한 무한급수근사식(無限級數近似式)을 사용하였다. 특히 CAERI 는 U이나 Pu과 같은 중원소(重元素)의 핵종분석시(核種分析時)에 직면(直面)하는 감마선과 U이나 Pu의 X-선(線)이 임의(任意)로 간섭(干涉)하며 공존(共存)하는 복잡한 스펙트럼까지도 취급(取扱)할 수 있다. $^{177m}Lu$감마선과 $^{235}U\;U_{\alpha}$X-선(線)의 시험(試驗)스펙트럼을 피팅하여, 다른 프로그램들의 피팅결과와 비교했을 때 좋은 일치(一致)를 보았다.

• Nuclear Engineering and Technology
• /
• 제19권4호
• /
• pp.292-309
• /
• 1987

미국 원자력 안전규제위원회(U.S. NRC)의 "원자로 위험도 참고문서(NUREG-1150)"에 입력자료로 제공하기 위해 실시한 Zion발전소 안전성 재평가 작입의 일환으로, 가상적 중대사고에 대한 대형건식 가압경수로 격납용기 반응해석을 수행하였다. 본 연구에서 사용한 방법론들은 Sandia 국립연구소에서 "중대사고 위험도 감소계획"의 일환으로 특히 Surry 발전소에 대한 연구를 위해 개발한 것이며, 이 방법론을 Zion발전소에 외삽법으로 적용하였다. 먹저, 원자력발전소의 위험도를 정량적으로 평가하는 주요절차를 개설하였다. 그리고, Zion발전소의 중대사고에 대한 격납용기 반응해석을 위해 사용한 방법론들을 상세히 기술하였다. 즉, 격납용기 반응해석을 위해 사용한 방법론들을 상세히 기술하였다. 즉, 격납용기 사건수목 해석 전산코드의 주요 특징과 격납용기 사건수목의 정량적 평가절차를 요약하여 높액다. 격납용기 반응해석에 있어서 중요한 발전소 고유의 특성과 본 연구의 불확실성 분석에 포함시킨 격납용기 하중과 성능에 관계되는 문제점들을 아울러 제시하였다. 끝으로, 가상적 증대사고에 대한 대형건식 가압경수로 격납용기의 반응에 대한 전망을 제공하기 위해서 결정적 및 통계학적 격납용기 사건수목 해설결과를 간단히 요약하여 제시하였다.설결과를 간단히 요약하여 제시하였다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
• /
• pp.250-257
• /
• 2007

항공기용 엔진은 설계 개발 단계에서 성능, 신뢰성, 안정성, 수명을 판단하는 시험에 엄청난 시간과 비용이 든다. 가상 엔진의 "Numerical Test Cell" 시험은 다분야 연계 해석을 통하여 하드웨어의 개발에 필요한 시간과 비용을 줄일 수 있다. 본 논문에서는 미국과 유럽에서의 전체 엔진 시뮬레이션 프로그램의 개발 활동을 소개한다. 미국의 NASA Glenn 연구소는 기존의 코드들을 결합하고 기능을 개선하여 NPSS를 개발하는 연구를 이끌고 있으며, 유럽에서는 대학, 연구소, 기업체로 구성된 VIVACE 컨소시움이 각 기관의 프로그램을 통합하여 PROOSIS를 개발하고 있다. 아울러 현재의 상황에 대한 고찰을 통하여 국내 개발의 가능성을 살펴보았다.

• Asian Journal of Atmospheric Environment
• /
• 제2권1호
• /
• pp.34-46
• /
• 2008

Emissions inputs for use in air quality modeling of Korea were generated with the emissions inventory data from the National Institute of Environmental Research (NIER), maintained under the Clean Air Policy Support System (CAPSS) database. Source Classification Codes (SCC) in the Korea emissions inventory were adapted to use with the U.S. EPA's Sparse Matrix Operator Kernel Emissions (SMOKE) by finding the best-matching SMOKE default SCCs for the chemical speciation and temporal allocation. A set of 19 surrogate spatial allocation factors for South Korea were developed utilizing the Multi-scale Integrated Modeling System (MIMS) Spatial Allocator and Korean GIS databases. The mobile and area source emissions data, after temporal allocation, show typical sinusoidal diurnal variations with high peaks during daytime, while point source emissions show weak diurnal variations. The model-ready emissions are speciated for the carbon bond version 4 (CB-4) chemical mechanism. Volatile organic carbon (VOC) emissions from painting related industries in area source category significantly contribute to TOL (Toluene) and XYL (Xylene) emissions. ETH (Ethylene) emissions are largely contributed from point industrial incineration facilities and various mobile sources. On the other hand, a large portion of OLE (Olefin) emissions are speciated from mobile sources in addition to those contributed by the polypropylene industry in point source. It was found that FORM (Formaldehyde) is mostly emitted from petroleum industry and heavy duty diesel vehicles. Chemical speciation of PM2.5 emissions shows that PEC (primary fine elemental carbon) and POA (primary fine organic aerosol) are the most abundant species from diesel and gasoline vehicles. To reduce uncertainties in processing the Korea emission inventory due to the mapping of Korean SCCs to those of U.S., it would be practical to develop and use domestic source profiles for the top 10 SCCs for area and point sources and top 5 SCCs for on-road mobile sources when VOC emissions from the sources are more than 90% of the total.

• Journal of Korean Vacuum Science & Technology
• /
• 제6권2호
• /
• pp.92-96
• /
• 2002

In this paper, we treated the Ni$_3$Al based alloy samples with intense pulsed ion beams (IPIB) at the beam parameters of 250KV acceleration voltage, 100 - 200 A/cm$^2$ current density and 60 u pulse duration. We simulated the thermal-mechanical process near the surface of Ni$_3$Al based alloy with our STEIPIB codes. The surface morphology and the cross-section microstructures of samples were observed with SEM, the composition of the sample surface layer was determined by X-ray Energy Dispersive Spectrometry (XEDS) and the microstructure on the surface was observed by Transmission Electron Microscope (TEM). The results show that heating rate increases with the current density of IPIB and cooling rate reached highest value less than 150 A/cm$^2$. The irradiation of IPIB induced the segregation of Mo and adequate beam parameter can improve anti-oxidation properly of IC6 alloy. Some craters come from extraneous debris and liquid droplets, and some maybe due to the melting of the intersection region of interphase. Increasing the pulse number enlarges average size of craters and decreases number density of craters.