• Nuclear Engineering and Technology
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• 제46권1호
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• pp.1-10
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• 2014

Probabilistic risk assessment (PRA) has been used in various technological fields to assist regulatory agencies, managerial decision makers, and systems designers in assessing and mitigating the risks inherent in these complex arrangements. Has PRA delivered on its promise? How do we gage PRA performance? Are our expectations about value of PRA realistic? Are there disparities between what we get and what we think we are getting form PRA and its various derivatives? Do current PRAs reflect the knowledge gained from actual events? How do we address potential gaps? These are some of the questions that have been raised over the years since the inception of the field more than forty years ago. This paper offers a brief assessment of PRA as a technical discipline in theory and practice, its key strengths and weaknesses, and suggestions on ways to address real and perceived shortcomings.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1951-1956
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• 2004

The transient nature and complex flow geometries of two-phase gas-liquid flows cause fundamental difficulties when measuring flow velocity using an electromagnetic flowmeter. Recently, a current-sensing flowmeter was introduced to obtain measurements with high temporal resolution (Ahn et $al.^{(1)}$). In this study, current-sensing flowmeter theory was applied to measure the fast velocity transients in slug flows. To do this, the velocity fields of axisymmetric gas-liquid slug flow in a vertical pipe were obtained using Volume-of-Fluid (VOF) method and the virtual potential distributions for the electrodes of finite size were also computed using the finite volume method for the simulated slug flow. The output signal prediction for slug flow was carried out from the velocity and virtual potential (or weight function) fields. The flowmeter was numerically calibrated to obtain the cross-sectional liquid mean velocity at an electrode plane from the predicted output signal. Two calibration parameters are required for this procedure: a flow pattern coefficient and a localization parameter. The flow pattern coefficient was defined by the ratio of the liquid resistance between the electrodes for two-phase flow with respect to that for single-phase flow, and the localization parameter was introduced to avoid errors in the flowmeter readings caused by liquid acceleration or deceleration around the electrodes. These parameters were also calculated from the computed velocity and virtual potential fields. The results can be used to obtain the liquid mean velocity from the slug flow signal measured by a current-sensing flowmeter.

• 미술이론과 현장
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• 제1호
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• pp.71-92
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• 2003

This study examined the condition of an educational discourse, relating the concept of creativity, culture, culture-centered, and critical thinking, to explore Culture-based Art Education(CBAE). In particular, art education practice was examined using interpretations of creativity and critical theory positions from the field of education. Discourse analysis was used as the research method to contextually situate and analyze the ways in which art education theory and practice of creativity and of critical studies encoded meanings. The study helped build an understanding that creativity was formed as a modernist discourse in the humanistic stance. In education, creativity became the fundamental concern for progressive educators who pursued innate ability of individuals. The way to enhance creative potential of students was to induce their motive, as was the same case in art education, while in artist training, free expression was its main method. In this way, as creativity was intimately connected with the concept of expression, in art education art making is the only course for enhancing creativity. However, because creative process cannot intelligently be regarded as logically distinct from the creative product, and creativity can only be said by product, it seems valid to think that creativity is the quality not to be achieved by teaching. Furthermore, its emphasis on art making resulted in unbalance of art making and art appreciation in art education. It was the late sixties when several alternatives for creative education were made their appearance. Critical studies in art adopted critical theory as its theoretical background has developed as an alternative of creative art education, when research and theory for creativity could not be adequate to deal with the problem of practice. Critical theory is a broad and diverse field of theory and practice drawing on aspects of the modernist perspective of the later Frankfurt School, feminism, Freirean pedagogy, postcolonial discourse as well as postmodernism to construct a practical approach to education. It is very this eclectic nature to provide the mosaic that need to experience cultures from different perspectives in a pluralistic society. Because one's personality is formed by multiple aspects of culture which is very complex and is made up of what we do and value, creativity cannot make part of educational discourse with the philosophy of culture centered. On the other hand, critical studies, as a school art program of critical theory, can perform the role of CBAE, because it would have to deal with the investigation of social and cultural issues form multiple personal, local, national, and global perspectives.

• 한국항해항만학회지
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• 제41권1호
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• pp.9-16
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• 2017

전 세계적으로 해양산업이 국가산업으로 인식되며 그 중요성이 커지고 있고, 해양산업 중 가장 각광 받는 분야는 해양레저 산업이라 할 수 있다. 또한 우리나라는 우수한 문화와 다양한 관광자원으로 많은 외국인 관광객이 방문하고 있다. 그 중 중국인 관광객인 유커의 경우 2007년 106만명을 시작으로 2015년 598만명까지 지속적으로 늘어나는 추세이다. 이에 인천시는 골든하버라는 이름의 복합리조트를 조성하기 위해 약 1조원 이상의 예산을 투입했으며, 향후 해양관광단지 개발에 집중할 것이라고 언급했다. 따라서 본 연구는 중국인 관광객과 인천항만공사의 전문가를 대상으로 해양관광단지의 성공요인에 대해 설문을 실시하여 차이를 비교하였다. 중국인 관광객 대상 퍼지분석 결과, 서비스 친절도(0.823)가 가장 높은 순위의 중요도를 보였고, 그 다음으로 안전성(0.823)과 편의성(0.773), 다양한 관광상품(0.755)을 중요하게 인식하는 것으로 나타났다. 운영사 대상 설문으로 골든하버의 운영사인 인전항만공사 직원 20명을 대상으로 실시하였고, 중요요인으로 다양한 관광상품(0.852), 접근성(0.850), 출입국심사(0.810), 편의성(0.793) 순으로 중요하게 인식하는 것으로 나타났다.

• 한국항공우주학회지
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• 제37권11호
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• pp.1066-1072
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• 2009

패널법(panel method)을 이용하여 포텐셜 유동조건에 있는 임의의 3차원 융합익기(Blended-Wing Body) 형상에 대해 정상/비정상 공력해석을 수행하였다. 본 연구 방법은 구간일정강도(piecewise constant strength) 용출(source) 및 중첩(doublet) 특이점(singularity)을 사용하고 Dirichlet 경계조건에 기초한 포텐셜 기저(potential based) 패널법과 물체고정좌표계의 각 방향에 대해 시간전진법(time-stepping method)을 결합한 방법이다. 본 프로그램은 임의의 3차원 BWB 형상 항공기의 공력해석을 빠르고 정확하게 수행할 수 있으며 BWB 항공기의 안정성을 위한 다양한 공력계수를 제공할 수 있다. 본 프로그램으로 3차원 정상/비정상 임의의 3차원 형상에 대하여 공력특성을 예측할 수 있어 BWB 항공기 설계단계, 비행 시뮬레이션과 같이 반복적 빠른 계산을 요구하는 실질적 응용에 크게 기여할 것이다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 1999년도 춘계공동학술대회:정보화시대의 지식경영
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• pp.426-426
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• 1999

;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.

• 한국환경복원기술학회지
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• 제17권3호
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• pp.75-86
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• 2014

An urban ecosystem is a complex system that includes social, economic and ecosystems. Therefore, it is important to consider its environmental capacity while developing a city plan. Most of the plans, however, consider only the social aspects, which fragments the green spaces and disturbs the movement of species. Sungnam has approximately 100 parks with unexecuted development plans and with great potential to contribute towards urban ecosystem enhancement. Therefore, this study applied network analysis to prioritize the development of city parks and contribute towards improving the green network, with Parus spp. as the target species. To compensate for the drawbacks of binary and possibility-based network analysis, this study included two indices, namely $BC^{PC}_K$, $BC^{IIC}_K$, $dPCconnector_k$ and $dIICconnector_k$. These indices make it possible to find patches that could play an important role in green network enhancement. The urban park with greater value gets a higher priority to be transformed into a park. Thus, our methodology could prove to be very useful in prioritizing the undeveloped parks, thereby supporting decision-making.

• The Journal of Asian Finance, Economics and Business
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• 제9권6호
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• pp.95-104
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• 2022

This study investigates the complex mechanism of work-family conflict affecting counterproductive behavior of employees based on resource conservation theory and 417 valid samples by using polynomial regression and response surface analysis. Counterproductive work behavior refers to any intentional behavior of an individual that has potential harm to the legitimate interests of the organization or its stakeholders. Results show that first, work-to-family conflict (WFC) and family-to-work conflict (FWC) had four matching types. Compared with "high WFC-low FWC," "low WFC-high FWC" and "low WFC-low FWC" matching conditions, the employee self-control resource depletion and counterproductive work behavior (CWB) are at their highest under "high WFC-high FWC" congruence matching condition. Second, the joint effect of WFC and FWC has a U-shaped relationship with counterproductive behavior. Compared with the "high WFC-low FWC" match state, the level of CWB in the "low WFC-high FWC" match state is higher. Third, the depletion of self-control resources played a mediating role in the effect of WFC on counterproductive behavior. Fourth, emotional intelligence moderated the relationship between the congruence of WFC and FWC and self-control resource depletion. Emotional intelligence was higher, and the positive relationship between the congruence of WFC and FWC and self-control resource depletion was weaker.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3285-3292
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• 2012

The interaction of thiazole drug with (6,0) zigzag single-walled boron nitride nanotube of finite length in gas and solvent phases was studied by means of density functional theory (DFT) calculations. In both phases, the binding energy is negative and presenting characterizes an exothermic process. Also, the binding energy in solvent phase is more than that the gas phase. Binding energy corresponding to adsorption of thiazole on the BNNT model in the gas and solvent phases was calculated to be -0.34 and -0.56 eV, and about 0.04 and 0.06 electrons is transferred from the thiazole to the nanotube in the phases. The significantly changes in binding energies and energy gap values by the thiazole adsorption, shows the high sensitivity of the electronic properties of BNNT towards the adsorption of the thiazole molecule. Frontier molecular orbital theory (FMO) and structural analyses show that the low energy level of LUMO, electron density, and length of the surrounding bonds of adsorbing atoms help to the thiazole adsorption on the nanotube. Decrease in global hardness, energy gap and ionization potential is due to the adsorption of the thiazole, and consequently, in the both phases, stability of the thiazole-attached (6,0) BNNT model is decreased and its reactivity increased. Presence of polar solvent increases the electron donor of the thiazole and the electrophilicity of the complex. This study may provide new insight to the development of functionalized boron nitride nanotubes as drug delivery systems for virtual applications.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.625-630
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• 2018

지르코니아와 금 표면 위에 형성된 메르캡토언데실인산층 사이에서 정전기적 상호작용이 규명되었다. 이를 위하여, 원자힘현미경(AFM)이 표면들 사이에서 pH값과 염 농도에 따라 작용하는 힘의 측정에 이용되었다. 측정된 힘은 Derjaguin-Landau-Verwey-Overbeek (DLVO) 이론으로 해석되어 각 조건에 대해서 표면의 정전기적인 특성들이 정량적으로 산출되었다. 이 표면 특성들의 염 농도와 pH에 대한 의존성이 질량보존의 법칙으로 예측된 결과와 일치하였다. pH 의존성은 표면 위의 이온화 기능기들로 설명될 수 있다. pH 4와 8에서 메르캡토언데실인산층이 지르코니아보다 더 많은 표면전하밀도와 전위차를 가지는 것은 그 층의 이온화 기능기들에 기인한 것으로 생각된다.