• 패션비즈니스
• /
• 제16권6호
• /
• pp.127-143
• /
• 2012

This study aims to derive the sensitive image analysing the color tones based on the web-sites of cosmetic brand and to know how the web-site color tones and the color tone image as visual factor for information transfer do influence the effective communication. 10 cosmetic brand web-sites are selected based on the pre survey, and the main page color tones of cosmetic brand web-site are analyzed by Color Catch and Munsell Conversion program, whereas the composition of color tones and color image such as the main trend colors, secondary colors, accent colors and etc are analyzed by a graphic professional program 'Adobe Photoshop'. 5 color tone groups are classified as Black&White, Green&White, Blue&White, Purple&White and Red&White according to the color distribution chart, and the emotional language is derived applying them to the pre research and IRI image scale. The color association is empirically analyzed by a survey method. The study results finally show Black&White is proper for expression of high quality and modern image, Green&White for pure and clean image, Blue&White for cool and transparent image, Purple&White for mysterious and elegant image respectively. This study results are necessary for plan of color delivering the strong transferring power of visual information the time when to make the effective web-sites, and it hopefully will be utilized as the basic data for the color marketing to actively express the brand identity and to satisfy the consumers' sensitivity.

• Nuclear Engineering and Technology
• /
• 제48권6호
• /
• pp.1412-1422
• /
• 2016

Austenitic stainless steels (ASSs) are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs) were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

• Nuclear Engineering and Technology
• /
• 제50권5호
• /
• pp.709-716
• /
• 2018

A criticality safety analysis was performed for the APR-1400 spent fuel pool region-II to ensure the safe storage of spent fuel, with credit taken for depletion and in-rack neutron absorbers (Metamic panels). PLUS7 fuel assembly was modeled using TRITON-NEWT of SCALE-6.1. The burnup-dependent cross-section library was generated under limiting core-operating conditions with 5%-w U-235 initial enrichment. MCNP5 was used to evaluate the neutron multiplication factor in an infinite array of rack cells with the axially nonuniformly burnt PLUS7 assemblies under normal, abnormal, and accident conditions; including all biases and uncertainties. The main purpose of this study is to investigate reactivity variations due to the critical depletion and reactor operation parameters. The approach, assumptions, and modeling methods were verified by analyzing the contents of the most important fissile and the associated reactivity effects. The Nuclear Regulatory Commission (NRC) guidance on k-eff being less than 1.0 for spent fuel pools filled with unborated water was the main criterion used in this study. It was found that assemblies with 49.0 GWd/MTU and 5.0 w/o U-235 initial enrichment loaded in Region-II satisfy this criterion. Moreover, it was found that the end effect resulted in a positive bias, thus ensuring its consideration.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제4권1호
• /
• pp.44-56
• /
• 2012

Autonomous Underwater Vehicles (AUVs) provide a useful means of collecting detailed oceano-graphic information. The hull resistance of an AUV is an important factor in determining the power requirements and range of the vehicle. This paper describes a procedure using Computational Fluid Dynamics (CFD) for determining the hull resistance of an AUV under development, for a given propeller rotation speed and within a given range of AUV velocities. The CFD analysis results reveal the distribution of the hydrodynamic values (velocity, pressure, etc.) around the AUV hull and its ducted propeller. The paper then proceeds to present a methodology for optimizing the AUV profile in order to reduce the total resistance. This paper demonstrates that shape optimization of conceptual designs is possible using the commercial CFD package contained in Ansys$^{TM}$. The optimum design to minimize the drag force of the AUV was identified for a given object function and a set of constrained design parameters.

• Nuclear Engineering and Technology
• /
• 제26권3호
• /
• pp.411-419
• /
• 1994

원자력발전소 중대사고시 예상되는 수소생성과 이에 따른 수소연소로 인한 압력증가로 야기되는 격납용기의 파손화률을 몬테카를로 방법을 통하여 계산하였다. 몬테카를로 계산을 수행하기 위해서는 각각의 입력변수들에 대한 적절한 확률분포함수가 요구되는데, 통계적인 처리를 통하여 구하였다. 고리 2호기에 대한 계산을 수행하였으며, 입력변수들에 대한 민감도 분석도 실시하였다. 고리 2호기에서 수소연소로 인한 격납용기의 파손확률은 60% 이하로 계산되었으며, 민감도 분석결과 SFD가 중요한 인자이긴 하지만 다른 인자들도 무시할 수 없는 영향을 미치고 있음이 밝혀졌다.

• 한국화재소방학회논문지
• /
• 제20권1호
• /
• pp.71-76
• /
• 2006

전기화재의 주된 원인은 단락 및 과부하 사고, 누전 및 접촉불량 등으로 구분되며, 화재의 발생요인은 이들 사고에서 동반되는 아크나 스파크로 인한 화재가 대다수이다. 저압배전선로에 사용되는 고감도형 누전차단기는 누전과 과부하를 검출하여 차단하는 기능은 있으나, 전기화재의 직접적인 위험요소인 아크나 스파크 현상에 대한 차단기능은 없는 것으로 분석된다. 이것은 저압 분전반에 적용되는 누전차단기의 경우 정격차단시간이 30[ms](KS C 4613)로 정해져 있어, 더욱 낮은 레벨로 주기적으로 발생되는 아크나 스파크를 감지하지 못하기 때문이다. 이러한 문제점을 개선하기 위하여 본 논문에서는 전기화재에 기인되는 아크나 스파크에 대해 누전차단기를 트립시키는 보조제어장치를 제안하고, 제안된 보조제어장치의 이론적 해석과 실험측정을 통해 그 타당성을 입증시킨다.

• 에너지공학
• /
• 제14권1호
• /
• pp.54-61
• /
• 2005

한국형 신형원자로1400(APR1400)은 3983MWt급의 2×4 루프 개량형 가압경수로(PWR)로서 대형 냉각재상실사고 발생시 안전주입수의 원자로용기 직접주입(DVI) 방식을 채택하고 있으며, 안전주입수탱크(SIT) 내부에 유량조절기(Fluidic Device, FD)를 장착하고 있다. 본 연구에서는 신형원자로 1400의 안전주입계통에 새로이 적용된 주요 특징 중 하나인 유량조절기에 대하여 최적안전해석코드인 TRAC-M/F90, 3.782버전을 이용한 성능평가 및 민감도 분석을 수행하였다. 연구결과 유량조절기가 안전주입수의 원자로 유입을 적절하게 조절하고 있음을 확인하였으며, 안전주입수탱크 내부의 압축질소체적 감소가 안전 주입수체적 감소에 비하여 노심의 급냉 완료 시점을 빠르게 하였다. 또한 안전주입계통의 전체 저항계수(K factor)가 최소 또는 최대일 때 노심의 급냉 완료 시점은 평균값인 경우보다 다소 늦어졌으나, 피복재 최고온도(PCT)는 상대적으로 큰 차이가 발생하지 않았다.

• 수산해양교육연구
• /
• 제28권5호
• /
• pp.1319-1328
• /
• 2016

Since Ballast Water Management Convention has been effected, BWTS, applied to new-building vessels and existing vessels, have been developed from many countries with various treatment methods. However, BWTS is mainly typed Electrolysis, Ozone and UV type. Approximately 70 products have been type approved by the Flag Administrations. For the new-building vessels, the vessels' design and construction have been considered for arrangements and installations for BWTS. However, existing vessels which already construction had finished have problem with selection of BWTS type for installation and arrangement. The selection of the most economized BWTS system is important though, CAPEX has not been made any significant differences. However, OPEX is more important factor. Consequently, detail analysis of OPEX is the key to the selection of the most economized BWTS system and also it can be the purpose of this study. The feasibility study on the main three type of BWTS (Electrolysis, Ozone and UV type) for 175K Bulk Carrier and 57K Cargo ship has been conducted for this study. Because, these three type of BWTS have been the most frequently installed and used and the two type of object vessels are consist of the 40% of the world merchant ship market. For this study, interest rate, project duration (operation time after installation), maintenance cost and fuel oil price are considered as major factor of feasibility study. In addition, expecting Interest rates to sensitivity analysis conducted for more accurate feasibility study. For 175K Bulk carrier, ozone treatment system is more economical than other types. For 57K cargo ship, UV type is considered more economical than other types. However, it is concluded that electrolysis type is more suitable compare to installation space, total weight and electrical power consumption.

• Journal of Radiation Protection and Research
• /
• 제18권1호
• /
• pp.71-82
• /
• 1993

원자력 발전소 작업과의 피폭량은 발전소의 안전 운영에 관한 척도일 뿐 아니라, 일반 대중이 원자력 발전의 안전을 평가하는 기본 요소이다. 또한, 최근 ICRP 60에 의한 개인 피폭선량 한도의 하향조정 권고는 지속적인 피폭저감에의 노력을 요구하고 있다. 본 논문에서는 작업자의 피폭저감에 관한 대안선정시 사용할 수 있는 최적화 기법을 제시하고 실제로 원전 운영자예 의해 제안된 대안들을 검토하는데 이 기법을 적용하여 보았다. 분석과정에서 기본분석이외에 가변 경제변수를 고려한 민감도 분석을 통해 계산 결과의 불확실성을 보완하였다. 분석결과를 살펴보면, 먼저 비용-이득 분석에서는 '증기 발생기 Nozzle Dam 및 Torquing Machine'이 총 이득면에서 가장 우수한 것으로 평가되었고, 다속성 효용 분석의 경우 'Co-No Seal 조임장치'가 가장 높은 효용을 가진 것으로 나타나 약간의 차이를 보이고 있다. 따라서, 최적화 기법의 적용시에는 두 가지이상의 정량적 기법을 보완적으로 사용하고, 정성적 인자도 충분히 고려하는 것이 필요하다.

• Nuclear Engineering and Technology
• /
• 제55권12호
• /
• pp.4447-4464
• /
• 2023

This paper focuses on the development of a new computational model of the CNESTEN's TRIGA Mark II research reactor using the 3D continuous energy Monte-Carlo code TRIPOLI-4 (T4). This new model was developed to assess neutronic simulations and determine quantities of interest such as kinetic parameters of the reactor, control rods worth, power peaking factors and neutron flux distributions. This model is also a key tool used to accurately design new experiments in the TRIGA reactor, to analyze these experiments and to carry out sensitivity and uncertainty studies. The geometry and materials data, as part of the MCNP reference model, were used to build the T4 model. In this regard, the differences between the two models are mainly due to mathematical approaches of both codes. Indeed, the study presented in this article is divided into two parts: the first part deals with the development and the validation of the T4 model. The results obtained with the T4 model were compared to the existing MCNP reference model and to the experimental results from the Final Safety Analysis Report (FSAR). Different core configurations were investigated via simulations to test the computational model reliability in predicting the physical parameters of the reactor. As a fairly good agreement among the results was deduced, it seems reasonable to assume that the T4 model can accurately reproduce the MCNP calculated values. The second part of this study is devoted to the sensitivity and uncertainty (S/U) studies that were carried out to quantify the nuclear data uncertainty in the multiplication factor k_eff. For that purpose, the T4 model was used to calculate the sensitivity profiles of the k_eff to the nuclear data. The integrated-sensitivities were compared to the results obtained from the previous works that were carried out with MCNP and SCALE-6.2 simulation tools and differences of less than 5% were obtained for most of these quantities except for the C-graphite sensitivities. Moreover, the nuclear data uncertainties in the k_eff were derived using the COMAC-V2.1 covariance matrices library and the calculated sensitivities. The results have shown that the total nuclear data uncertainty in the k_eff is around 585 pcm using the COMAC-V2.1. This study also demonstrates that the contribution of zirconium isotopes to the nuclear data uncertainty in the k_eff is not negligible and should be taken into account when performing S/U analysis.