• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.680-683
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• 2005

The wing component model for flutter analysis consisting of stiffness, mass, and aerodynamic model has been constructed based on the full airframe finite element model for 4-seat canard-type small aircraft. A study on wing flutter characteristics has been investigated based on the wing component model constructed using PK method in MSC/NASTRAN for flutter analysis. In addition, wing flutter mechanism for the aircraft under consideration has been analyzed based on the results of normal mode and flutter analysis.

• Journal of Pharmaceutical Investigation
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• 제36권6호
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• pp.377-383
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• 2006

The purpose of the present study was to examine the pharmacokinetic characteristics of arsenic hexaoxide($As_4O_6$), a novel anticancer compound, after i.v. bolus and oral administration in rats. We developed an ICP-Mass based method to analyze arsenic hexaoxide levels in plasma, bile, urine, feces, and tissue and validated the method. Arsenic hexaoxide rapidly disappeared from the plasma by 10 min($\alpha$ phase) after i.v. administration, which was followed by the late disappearance in the $\beta$ phase. The mean plasma half-lives($t_{1/2}$) of arsenic hexaoxide at the a and $\beta$ phase when administered at a dose of 5 mg/kg were 1.57 and 29.8 min, respectively. The maximum plasma concentration($C_{max}$) was 230 ng/mL, after oral administration of arsenic hexaoxide at a dose of 50 mg/kg. The bioavailability, which was calculated from the dose-adjusted ratio, of the oral administered arsenic hexaoxide was 1.61%. Of the various tissues tested, arsenic hexaoxide was mainly distributed in the spleen, lung, liver and kidney after oral administration. Arsenic hexaoxide levels in the spleen or lung at 24 hr after oral administration were higher than those of maximum plasma concentration($C_{max}$). The cumulative amounts of arsenic hexaoxide found in the urine by 48 hr after the administration of 50 mg/kg were 5-fold higher than those in the bile. However, the cumulative amounts in the feces were 10-fold higher compared with those of urine, suggesting that arsenic hexaoxide is mostly excreted in the feces. In conclusion, our observations indicated that arsenic hexaoxide was poorly absorbed from the gastro-intestinal tract to the blood circulation and transferred to tissues such as the spleen and lung at 24 hr after oral administration. Moreover, the majority of arsenic hexaoxide appears to be excreted in the feces by 48 hr after oral administration.

• 한국시뮬레이션학회논문지
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• 제30권2호
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• pp.23-31
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• 2021

개체단위 M&S의 교전 결과에 대한 정확도를 높이기 위해서는 신뢰성 있는 무기효과지수를 바탕으로 피해 정도가 모의되어야 한다. 무기효과지수는 특정 교전 환경에서 무기체계와 표적에 대한 명중확률(Ph)과 살상확률(Pk)을 지수화한 값으로, 주로 JMEM 데이터나 JMEM 방법론에 따라 생산된 데이터가 활용되고 있다. 그러나 JMEM 방법론은 표적 중심부를 기준으로 원형공산오차를 통과하는 파편이나 탄의 격자 통과량으로 살상확률을 계산하기 때문에 지형, 대기, 장애물 등의 추가적인 환경 요소를 고려하기 위해서는 전문가에 의한 보정이 요구된다. 따라서 본 논문에서는 다수의 교전 및 환경요소가 반영된 무기효과지수 생산을 위해 공학급 무기체계 모델을 활용하여 몬테카를로 시뮬레이션을 수행하고, 그 결과 데이터를 바탕으로 메타모델을 생성하였다. 명중확률과 살상확률 메타모델로 로지스틱 회귀모델과 가우시안 프로세스 회귀모델이 각각 생성되었으며, 예시 시나리오에 적용하여 모델 적합도를 관찰하였다. 본 연구에서 제시한 절차를 따르면 개체단위 M&S의 입력자료를 효율적으로 생산할 수 있을 것으로 기대한다.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1132-1138
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• 2009

The spring constants of primary suspensions for a railway vehicle are optimized by a robust design process, in which the response surface models(RSMs) of their dynamic responses are constructed via the design of experiment(DOE). The robust design process requires an intensive computation to evaluate exactly a probabilistic feasibility for the robustness of dynamic responses with their probabilistic variances for the railway vehicle. In order to overcome the computational process, the process capability index $C_{pk}$ is introduced which enables not only to show the mean value and the scattering of the product quality to a certain extent, but also to normalize the objective functions irrespective of various different dimensions. This robust design, consequently, becomes to optimize the $C_{pk}$ subjected to constraints, i.e. 2, satisfying six sigma. The proposed method shows not only an improvement of some $C_{pk}$ violating the constraints obtained by the conventional optimization, but also a significant decrease of the variance of the $C_{pk}$.

• 한국초지조사료학회지
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• 제6권3호
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• pp.138-144
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• 1986

본(本) 시험(試驗)은 독일(獨逸)의 남부지방(南部地方)인 Bayern Alps 지역(地域)의 2차천이(次遷移) 식생(植生)인 Carex ferruginea 우점(優占) 군락지(群落地)에서 PK-시비(施肥) 및 면양(緬羊) 방목(放牧)에 依(依)한 걸뿌림 초지(草地)의 식생유지(植生維持) 및 자연초지(自然草地)의 개량(改良)을 생태학적(生態學的)인 면(面)에서 연구(硏究)코자 1980년 4월부터 1983년 10월까지 수행(遂行)되었으며 식생변화(植生變化)에 대(對)한 조사(調査) 방법(方法)으로는 Releve-method, Point-Interecept-method 및 Quadrat-Charting-method 등(等)이 이용(利用)되었다. 1. PK-시비(施肥) 및 면양(緬羊) 방목(放牧)에 의(依)해 겉뿌림 초지(草地)의 사료가(飼料價)는 점차(漸次) 증가(增加)되었으며, 시비(施肥)를 하지 않고 방목(放牧)만 실시(實施)한 곳은 초지(草地)의 사료가(飼料價)가 차츰 감소(減少)되었다, 2. 2차천이(次遷移) 식생(植生)인 자연초지(自然草地)의 품종(品種)(초지가(草地價)은 시비(施肥) 및 방목(放牧)에 의(依)해 시험(試驗) 2년차(年次) 가을에 겉뿌림 초지(草地)와 대등(對等)하게 크게 증진(增進)되었으며 시비(施肥)없이 방목(放牧)만 실시(實施)한 자연초지(自然草地)의 사료가(飼料價)는 증가(增加)되지 않았다. 3. 자연초지(自然草地)에서 PK-시비(施肥)의 영향(影響)은 방목(放牧) 보나 우수(優秀)하였으며, 섭초류(涉草類)는 시비(施肥)에 의(依)해 거의 소멸(消滅)되었고, 화본과(禾本科) 및 두과(荳科)는 크게 증가(增加)되었으며, 시비(施肥)를 하지 않고 면양(緬羊) 방목(放牧)만 실시(實施)한 구(區)는 두과목초(荳科牧草)가 점차(漸次) 감소(減少)되었다. 특(特)히 6월과 10월의 섭초(涉草)의 수량(收量) 비율(比率)이 크게 차이(差異)가 있었는데 이것은 재생력(再生力) 결핍(缺乏)에 기인(基因)되었다. 4. PK-시비(施肥) 및 면양(緬羊) 방목(放牧)에 의(衣)해 시험전(試驗前)의 Carex ferruginea 우점(優占) 초지(草地) 군락(群落)은 기름진 산지초지형(山地草地型)인 Alchemillo-Cynosuretum으로 천이(遷移)되었다.

• 대한안전경영과학회지
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• 제16권1호
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• pp.169-176
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• 2014

This research discusses the characteristics and the implementation strategies for two types of quality metrics to analyze innovation effects in six sigma projects: fixed specification type and moving specification type. $Z_{st}$, $P_{pk}$ are quality metrics of fixed specification type that are influenced by predetermined specification. In contrast, the quality metrics of moving specification type such as Strictly Standardized Mean Difference(SSMD), Z-Score, F-Statistic and t-Statistic are independent from predetermined specification. $Z_{st}$ sigma level obtains defective rates of Parts Per Million(PPM) and Defects Per Million Opportunities(DPMO). However, the defective rates between different industrial sectors are incomparable due to their own technological inherence. In order to explore relative method to compare defective rates between different industrial sectors, the ratio of specification and natural tolerance called, $P_{pk}$, is used. The drawback of this $P_{pk}$ metric is that it is highly dependent on the specification. The metrics of F-Statistic and t-Statistic identify innovation effect by comparing before-and-after of accuracy and precision. These statistics are not affected by specification, but affected by type of statistical distribution models and sample size. Hence, statistical significance determined by above two statistics cannot give a same conclusion as practical significance. In conclusion, SSMD and Z-Score are the best quality metrics that are uninfluenced by fixed specification, theoretical distribution model and arbitrary sample size. Those metrics also identify the innovation effects for before-and-after of accuracy and precision. It is beneficial to use SSMD and Z-Score methods along with popular methods of $Z_{st}$ sigma level and $P_{pk}$ that are commonly employed in six sigma projects. The case studies from national six sigma contest from 2011 to 2012 are proposed and analyzed to provide the guidelines for the usage of quality metrics for quality practitioners.

• Journal of Ginseng Research
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• 제44권1호
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• pp.105-114
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• 2020

Background: Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies. Methods: A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS² mode. Finally, multiple reaction monitoring transitions transformed from MS² of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method. Results: The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG-RP). Significant changes in PK parameters were observed before and after combination. Conclusion: Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.330-342
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• 2017

Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate ($KH_2PO_4$) and dipotassium hydrogen phosphate ($K_2HPO_4$), Plackett-Burman design was applied. The $MgSO_4$, $FeSO_4$, and $CuSO_4$ showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM $MgSO_4$, 0.33 g/l $FeSO_4$ and 1.41 mM $CuSO_4$ were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.

• 미생물학회지
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• 제44권2호
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• pp.130-134
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• 2008

미생물 자동배양기를 이용한 감염성 물질의 검출은 시험적 오차의 경감은 물론 분리율 향상과 시간 단축을 가능하게 하였다. BacT/ALERT 3D 자동배양기는 미생물성장 시 발생되는 이산화탄소를 비색법으로 검출하는 장비로서 임상시료를 이용한 미생물 배양과 검출에 이용되어왔다. 자동배양기의 효율성을 검증하고 의약품의 무균 시험에 적용가능한지를 평가하기 위하여 6종의 세균을 이용하여 중식 및 검출특성을 분석하였다. 3종의 호기성세균 Pseudomonas aeruginosa, Micrococcus Iuteus, Bacillus subtilis와 Staphylococcus aureus는 1 CFU가 31.44 시간 내에 검출되었고, 혐기성균인 Clostridium sporogenes는 15.96시간에 균의 중식이 감지되었다. 저성장 혐기성세균인 Propionibacterium acnes는 $10^4$ CFU의 균수에서 검출에 129.36시간이 소요되었다. 이 같은 결과는전통적 직접 배양법보다 검출감도에 있어서 $10\sim10^5$배 높고 검출시간을 $2\sim10$10시간 단축한 것으로서 자동배양법이 미생물 증식과 검출에 효율적임을 말해준다. 따라서 본 시험에서 이용한 자동배양법은 임상시료에서의 감염원 진단뿐 아니라 생물의약품의 무균시험에 이용 가능하다고 판단된다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제1권1호
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• pp.55-63
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• 2001

In this paper, we utilize the asymptotic variance of $C_{pk}$ to propose a two-sided confidence interval based on percentile-t bootstrap method. This confidence interval is compared with the ones based on the standard and percentile bootstrap methods. Simulation results show that percentile-t bootstrap method is preferred to other methods for constructing the confidence interval.l.