• Advances in aircraft and spacecraft science
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• 제10권6호
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• pp.521-543
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• 2023

Reynolds-averaged Navier-Stokes (RANS) models are extensively employed in industrial settings for the purpose of simulating intricate fluid flows. However, these models are subject to certain limitations. Notably, disparities persist in the Reynolds stresses when comparing the RANS model with high-fidelity data obtained from Direct Numerical Simulation (DNS) or experimental measurements. In this work we propose an approach to mitigate these discrepancies while retaining the favorable attributes of the Menter Shear Stress Transport (SST) model, such as its significantly lower computational expense compared to DNS simulations. This strategy entails incorporating an explicit algebraic model and employing a neural network to correct the turbulent characteristic time. The imposition of realizability constraints is investigated through the introduction of penalization terms. The assimilated Reynolds stress model demonstrates good predictive performance in both in-sample and out-of-sample flow configurations. This suggests that the model can effectively capture the turbulent characteristics of the flow and produce physically realistic predictions.

• 한국산림과학회지
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• 제98권1호
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• pp.66-81
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• 2009

'환경을 조성하고 보전하는 인간과 문화'의 새로운 시각에서 지속가능한 숲 관리는 '문화적 지속가능성' 개념으로 재구성할 수 있다. 문화적 지속가능성은 환경을 조성하고 보전하는 문화의 높은 기여도를 강조하는 것이다. 본 연구는 근세조선의 '문화사회적 임업'의 역사적 사례를 통해서 현대의 문화적 지속가능성에 필요한 함의들을 추출하는 데에 그 목적이 있다. 조선의 첫 번째 왕이었던 태조와 관련하여 소나무(Pinus densiflora)는 조선의 왕목이었고 왕도정치의 이념을 지지하는 성리학적 신앙과 예제 체제 속에서도 가장 상위에 속하는 사직제례와 관련 있는 사직수(社稷樹)였다. 사직 제례의 숭배대상은 토지신(社)과 곡식신(稷)인데 고대 사회의 수목신앙을 이으면서 유교적 신앙 및 예제에 편입된 것이 토지신이며 토지신의 구체적 모습이 사직수이다. 왕목과 사직수로서의 소나무는 조선 왕실 통치의 종교-정치적 정통성을 지지하는 중요한 역할을 담당하였다. 소나무의 종교-정치적 상징성은 여러 측면으로 표현되었다. 소나무는 조선 조정이 주관하는 예제가 봉행되는 신전과 사당을 위해서도 물적 기반으로도 쓰였다. 소나무의 이런 역할은 왕실 능원림, 왕실 관곽재를 위한 황장봉산의 소나무 숲, 왕의 거처 도성 내외사산 소나무 숲의 조성, 방제, 보전, 관료적 관리로 확대 표현되었다. 문화사회적 임업의 역사적 사례인 이러한 소나무 숲의 종교-정치적 관리 체계는 조선의 경제적인 숲 관리 체계인 송정이나 조선 전기의 의송처와 금산의 소나무 숲 및 조선 후기의 봉산 체계의 소나무 숲의 경영과도 비교가 가능하고 공통성과 고유성을 함께 보여준다. 왕실의 소나무 문화는 대중적 의식에도 영향을 끼쳐 백성들이 금표가 있는 능원림, 금산, 봉산에서 시행된 금양(禁養)된 토지 또는 숲과 바꾸어 쓸 수도 있는 '말림갓'이라는 순한국어 단어를 형성하게 만든 것으로 보인다. 근세조선은 사직단, 능원림, 황장금산 및 황장봉산, 도성내외 사산의 소나무숲을 대상으로 하는 문화사회적 임업을 실행하였다. 조선 시대 소나무 숲의 보전과 경영에는 풍수지리, 민속신앙, 불교적 요소가 통합된 조선의 성리학적 신앙과 예제가 경제적 목적보다도 더욱 중요한 역할을 담당하였다. 인간과 환경의 상호작용이 여러 세대를 걸쳐 장기적인 문화-자연적 평형이나 균형을 이루는 것이 문화적 지속가능성인데, 숲과 환경을 조성하고 보전하는 현대인이 문화-자연 유산을 발굴하고 여러 세대에 걸친 보전으로 변환하며, 문화적, 사회적, 정신적 필요를 충족하는 환경과 인간의 상호작용에 대한 초학제적 지식인 지속가능성 과학 지식을 생산하는 것이 중요하다는 것이 근세조선의 사례 연구의 함의로 추출되었다.

• 항공우주정책ㆍ법학회지
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• 제34권1호
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• pp.3-38
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• 2019

항공운송에서 법령상 의무를 위반한 사업자에 대해 행정부는 정해진 절차에 따라 행정제재를 조치할 수 있는데, 그 중 대표적인 것이 금전적인 행정제재인 과징금이다. 행정제재로서 과징금 부과제도는 1980년대 공정거래 분야에서 우리나라에 처음 도입되었는데, 항공관련 법령에서의 도입은 1984년 개정 <항공법>에서 이루어졌다. 현재 항공 관련 과징금은 <항공사업법>이나 <항공안전법>에 규정되어 있다. 법률에 따르면 항공 사업자가 행정상 의무를 위반하여 영업의 정지를 명하거나, 부여한 자격증명이나 승인의 효력을 정지하는 것이 사업의 이용자 등에게 심한 불편을 주거나 공익을 해칠 우려가 있는 경우에 그러한 정지조치에 갈음하여 과징금이 부과될 수 있다. 이점에서 항공관련 과징금은 우리나라 과징금 제도의 원류라 할 수 있는 공정거래 분야의 과징금과 다소 차이를 보인다. 공정거래 분야에서는 시장경제 질서의 가치를 훼손하는 행정상 의무위반 행위에 대해 과징금이 부과되고, 위반행위에 따른 이익의 환수와 소비자의 부당한 지출을 보상하는 역할에 주목한다. 하지만 항공분야에서 사업자의 의무위반행위는 단순히 국민의 재산적 손실을 발생시키는 것이 아니라, 항공교통이용자의 생명이나 신체에 직접적인 영향을 끼치게 된다. 이점에서 항공 과징금은 공정거래 분야의 과징금과 비교할 때 부당이득의 환수 보다는 행정행위의 실효성 확보 수단으로서 행정적 제재 혹은 징벌의 성격을 강하게 가진다. 일반적으로 과징금은 행정 전문가에 의한 조사절차를 거치므로 효율성이 확보될 수 있고, 사법적 절차에 비해 신속한 집행이 가능하다는 점에서 행정적 제재수단으로 선호도가 높다. 더욱이 민사소송에서 징벌적 손해배상이 인정되지 않는 우리나라 현실에서 국민의 법 감정을 인지하여 사업자에게 철퇴를 가함으로써, 과징금 부과제도는 사회정의를 실현하는 수단으로 인식되어 있고 이에 대한 여론도 상당히 호의적이다. 하지만 과징금은 어디까지나 행정행위의 실효성 확보수단일 뿐이다. 우리나라 항공관련 법률에 따른 과징금은 행정적 제재수단이면서 그 실효적인 측면에서는 형벌의 일종인 벌금과 유사하고, 더욱이 지나치게 고액의 과징금으로 인해 국가의 형벌권 집행 이상의 결과를 가져오는 경우도 있다. 나아가 과징금 부과제도의 부적절한 입법과 그 운영은 자칫 법치국가로서의 가치를 훼손할 우려를 낳기도 한다. 위와 같은 인식 하에서 본 논문은 우리나라 항공관련 법령에 규정된 과징금 부과제도와 운영현황에 관한 현주소를 파악할 목적에서 기술되었다. 특히 외국의 항공관련 과징금 법령과의 비교 연구를 통하여 우리 제도의 문제점과 개선방향을 탐구하는데 주력하였다. 아무쪼록 본 연구를 통해 우리나라 항공 산업의 발전과 공공의 이익이 함께 추구될 수 있는 방향으로 항공관련 과징금 부과제도가 합리적으로 운영되기를 희망한다.

• 보건행정학회지
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• 제23권1호
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• pp.19-34
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• 2013

Background: The study describes the changes resulted from imposition on tertiary hospital outpatient coinsurance rate rise policy and in tertiary or general hospital drug coverage rise policy on healthcare service utilization. Methods: Accordingly, the hypothesis about outpatient healthcare utilization after rise policy in outpatient coinsurance rate and drug coverage was established, using interrupted time-series analysis and segmented regression analysis to test the hypothesis. 5-year analysis period (2007. 3-2012. 3) from the outset year was designated, the data about most common 10 high-ranking of the main diseases targeting visiting patient from age of 6 to 64 were collected. Results: The summary on the major research is followed. First, the medical expense and duration of treatment tends to be increased in case of imposition about rise policy in outpatient coinsurance rate in the tertiary hospital under the interrupted time-series analysis. It showed temporary increase and slow down on account of influenza A even after the policy enforcement. In segmented regression analysis, duration of visit and medical expense in the tertiary hospital increased temporally right after the policy implementation and the decreased rapidly depends on period. Both rise and fall is statistically significant. The second, In case of tertiary or general hospital outpatient drug coverage rise policy, all of the tertiary hospital healthcare service utilization variables by the interrupted time-series analysis, drug coverage policy in the general hospital deeply declined according to decreasing trend before policy implementation. The third, in case of segmented regression analysis, the visit duration and medical expense statistically declined right after the policy implementation in both the tertiary and general hospital. Meanwhile, administration day was statistically meaningful only for the decrease right after the policy implementation. Otherwise, general hospital changes are not statistically meaningful. And the medicine cost was statistically, meaningfully decreased after the increase in drug coverage. Conclusion: Finally, the result demonstrated according to the analysis is only 1 hypothesis is denied, the other 2 are partially supported. Then, tertiary hospital outpatient coinsurance rate increase policy comparatively makes decrease effect on long-term healthcare utilization, and tertiary or general hospital outpatient drug coverage policy showed partially short-term effect is assured.

• 한국환경복원기술학회지
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• 제14권6호
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• pp.97-109
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• 2011

Korea introduced the cooperation charge on conservation of ecosystem for minimizing damage of ecosystem due to development projects and their effects and for preparing resources for natural environment conservation projects. Advanced countries have made efforts by expanding investment in natural environment conservation and restoring projects to promote prevention of global warming and improvement of biological diversity, are establishing nationwide strategies and plans. To examine the reality of projects by returns of the cooperation charge on conservation of ecosystem, microsite projects in schools and public facilities take the largest share while their project budgets are only about 100~300 KRW, relatively small, which might be attributable to budget restrictions in accordance with the calculating method of levying cooperation charge on conservation of ecosystem and problems of project proceeding in the system of returning fund for projects in general. The conclusion which this study suggests on invigoration of cooperation charge on conservation of ecosystem and its operation are as followings. First, although the cooperation charge on conservation of ecosystem has been introduced in 2001, the amount of imposition per unit area remains unchanged. It is desirable to increase the amount into $1,400KRW/m^2$ as of August, 2011 as the price index has been continuously rising for the past 10 years and the upward adjustment of imposition per unit area should be notified by the decree of the Ministry of Environment every January. Second, the ceiling amount of the cooperation charge on conservation of ecosystem should be abolished. Now the ceiling amount is defined as 1 billion KRW but it was found that there was not any ceiling amount specified according to the comparative analysis of similar systems with the Korean environmental improvement fund. The ceiling should be abolished so that medium level businesses are carried out and ecosystem recovering projects in the true sense of the word can be made smoothly. Third, weight should be introduced in calculating amounts in accordance with ecologic and economic values. Harmony between development and environment can be achieved by applying differentiated weights of constant regional coefficient by use zone and ecologic and economic values. Continuous efforts of improving cooperation charge on conservation of ecosystem should be made more than anything else so that projects by returns of cooperation charge on conservation of ecosystem get effectiveness.

• 한국전산유체공학회지
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• 제13권4호
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• pp.13-23
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• 2008

This paper is an extension of previous study[1] on a development of a divergence-free element method using a hermite interpolated stream function. Divergence-free velocity bases defined on rectangles derived herein produce pointwise divergence-free flow fields. Hence the explicit imposition of continuity constraint is not necessary and the Galerkin finite element formulation for velocities does not involve the pressure. The divergence-free element of the previous study employed hermite (serendipity) cubic for interpolation of stream function, and it has been noted a possible discontinuity in variables along element interfaces. This deficiency can be removed by use of a hermite bicubic interpolated stream function, which requires four degrees-of-freedom at each element corners. Those degrees-of-freedom are the unknown variable, its x- and y-derivatives and its cross derivative. Detailed derivations are presented for both solenoidal and irrotational basis functions from the hermite bicubic interpolated stream function. Numerical tests are performed on the lid-driven cavity flow, and results are compared with those from hermite serendipity cubics and a stabilized finite element method by Illinca et al[2].

• Food Science and Biotechnology
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• 제17권3호
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• pp.603-607
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• 2008

Thirteen commercial antimicrobial products were examined to assess the sporicidal activity against Bacillus cereus spores at room temperature, 60 and $85^{\circ}C$. Neither the antimicrobials showed detectable antimicrobial activity against the B. cereus spores nor induced spore germination after the treatment at 0.5 or 1.0%(w/v, v/v) commercial antimicrobial agents at room temperature for 0.5 to 4 hr. However, when the antimicrobials such as chitosan, lactic acid, fermented pollen, grapefruit extract were applied with heat at $85^{\circ}C$ for 30 min, more than 1 log CFU/mL spores were additionally inactivated compared to only heat treatment without antimicrobials. Imposition of $60^{\circ}C$ to B. cereus spores with the higher concentration of 5.0%(v/v) lactic acid or 2.5%(w/v) thiamine dilaurylsulfate for the longer time incubation of 24 hr resulted in 3 log CFU/mL spore inactivation. This work showed that low concentrations of commercial antimicrobials by themselves did not inactivate B. cereus spores. However, when physical processes such as heat were combined together, antimicrobials showed a synergistic effect against B. cereus spores.

• 통상정보연구
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• 제8권2호
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• pp.211-226
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• 2006

This paper discusses the definition of the term "domestic industry" in relation to the application of the safeguards provisions of the WTO through the judicial interpretation made by the WTO Appellate Body and panel. The requirements for the imposition of safeguards include a rapid increase in import quantity, the existence of serious injury or threat of serious injury to the domestic industry, and a causal relationship between the increase in imports and the industrial injury. The domestic industry refers to the producers that account for a considerable portion of the total national production, or the national producers who produce articles "like" or "directly competitive" with the specific imports. Chronically, there have been controversial disputes relating to the interpretation of the term "like" or "directly competitive". Reviewing the disputes relating to the term "domestic industry" in application of the safeguards provisions since the establishment of the WTO, the interpretation of the term "like" has been made imposing weight on the physical characteristics of the products. This interpretation is in contrast with that of the interpretation of the term "directly competitive" which has been interpreted with imposed weight on the commercial elasticity of substitution which can be measured by the final use or consumer's taste.

• 한국생산제조학회지
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• 제6권4호
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• pp.108-117
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• 1997

A continuum analysis has been performed for the application to the thermo-elasto-plastic behavior in a discontinuous metal matrix composite. an FEM (Finite Element Method) analysis was implemented to obtain the internal field quantities of composite as well as overall composite behavior and an experiment was demonstrated to compare with the numerical simulation . As the procedure, a reasonably optimized FE mesh generation, the appropriate imposition of boundary condition , and the relevant post processing such as elastoplastic thermomchanical analysis were taken into account. For the numerical illustration, an aligned axisymmetric single fiber model with temperature dependent material properties and precipitation hardening effect has been employed to assess field quantities. It was found that the residual stresses are induced substantially by the temperature drop during the thermal treatment and that the FEM results of the vertically and horizontally constrained model give a good agreement with experimental data.with non-woven carbon mat is about 24% higher than that of composite materials without non-woven carbon mat. Transverse tensile strength and torughness also increase by inserting non-woven carbon mat between layers.

• 한국가시화정보학회지
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• 제1권1호
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• pp.64-74
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• 2003

An experimental study was carried out to investigate the effect of periodic blowing and suction on a turbulent boundary layer. Particle image velocimetry (PIV) was used to probe the characteristics of the flow. The local forcing was introduced to the boundary layer via a sinusoidally-oscillating jet issuing from a thin spanwise slot. Three forcing frequencies (f$^{+}$=0.044, 0.066 and 0.088) with a fixed forcing amplitude (A$^{+}$=0.6) were employed at $Re_{=690. The effect of the forcing angles ($\alpha$=60$^{\circ}$ , 90$^{\circ}$ and 120$^{\circ}$ ) was investigated under the fixed forcing frequency (f$^{+}$=0.088). The PIV results showed that the wall region velocity decreases on imposition of the local forcing. Inspection of phase-averaged velocity profiles revealed that spanwise large-scale vortices were generated in the downstream of the slot and persist further downstream. The highest reduction in skin friction was achieved at highest forcing frequency (f$^{+}$=0.088) and a forcing angle of $\alpha$=120$^{\circ}$. The spatial fraction of the vortices was examined to analyze the skin friction reduction.