• 대한의생명과학회지
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• 제18권1호
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• pp.10-15
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• 2012

A 12-week repeated-dose oral toxicity study of water-soluble Orostachys japonicus extract (WOJ) was performed in Sprague-Dawley (SD) rats of both genders. Each group of ten rats was orally administered in doses of either 0 or 250 mg/day over a 12-week period. As a result, no WOJ-related changes were observed in terms of survival rate, clinical signs, body weight, or food intake. In addition, no difference in organ weight between the control and treated groups was detected. Furthermore, serum biochemistry parameters revealed some changes within normal ranges although significant decreases in total-bilirubin in the females. In spite of some alterations in serum biochemistry, the clinical signs, body weight changes from food intake, and autoptical remarks indicated that WOJ was not toxic. This study suggests that repeated treatment of O. japonicus very low toxicity and the NOAEL (no observed adverse effect dose) of WOJ exceeds 250 mg/kg in the SD rats.

• Structural Engineering and Mechanics
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• 제52권5호
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• pp.903-918
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• 2014

Large space structures may have resonant low eigenvalues and often these appear with closely-spaced natural frequencies. Owing to the coupling among modes with closely-spaced natural frequencies, each eigenvector corresponding to closely-spaced eigenvalues is ill-conditioned that may cause structural instability. The subspace to an invariant subspace corresponding to closely-spaced eigenvalues is well-conditioned, so a method is presented to design the feedback control law of intelligent structures with closely-spaced eigenvalues in this paper. The main steps are as follows: firstly, the system with closely-spaced eigenvalues is transformed into that with repeated eigenvalues by the spectral decomposition method; secondly, the computation for the linear combination of eigenvectors corresponding to repeated eigenvalues is obtained; thirdly, the feedback control law is designed on the basis of the system with repeated eigenvalues; fourthly, the system with closely-spaced eigenvalues is regarded as perturbed system on the basis of the system with repeated eigenvalues; finally, the feedback control law is applied to the original system, the first order perturbations of eigenvalues are discussed when the parameter modifications of the system are introduced. Numerical examples are given to demonstrate the application of the present method.

• Elastomers and Composites
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• 제49권4호
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• pp.336-340
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• 2014

본 연구에서는 광촉매 작용을 하는 이산화티타늄 광촉매를 polyester 섬유에 코팅하여 탈취, 항균 및 자외선 차폐에 대한 기능을 부여하고 그 특성을 알아보았다. 그 결과 탈취성능은 세탁 전과 반복 20회 세탁 후에도 97%이상 저감되는 것으로 나타났으며, 항균성은 균수가 99.9%이상 감소되는 것으로 나타났다. 그리고 Polyester 섬유를 20회 반복 세탁을 행하여도 이산화티타늄 광촉매의 이탈 없이 표면에 견고하게 부착되어 있음을 확인하였으며, 또한 가스분해성능도 세탁전과 20회 반복 세탁 후에도 유지하는 것으로 나타나 세탁내구성이 우수함을 확인하였다. 자외선 차폐성도 세탁 전과 비교하여 20회 반복 세탁 후에도 83%이상 차단되는 것으로 나타났다.

• 약학회지
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• 제40권5호
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• pp.545-549
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• 1996

Male Sprague-Dawley rats were exposed to the toluene at 3,000${\pm}$200ppm via inhalation for two hours in the single inhalation group and three weeks by two hours per day, six da ys per week in the repeated inhalation group. The blood toluene concentration in the repeated inhalation group was significantly lower than that in the single inhalation group after 210 and 240 minutes of exposure. The peak concentration of blood toluene was 58.13${\pm}$4.63${\mu}$g/ml in the single inhalation group and 54.24${\pm}$6.87mcg/ml in the repeated at the end of 120 minutes of the exposure. The behavioral change of rats for the initial 30 minutes of the toluene inhalation showed mildly increased movement and excitement but remained calm and inhibitory behaviors after that period; more inhibitory behaviors in the single inhalation group compared with the repeated inhalation group. In open-field test, after the termination of the toluene inhalation, no difference had been statistically observed between the toluene inhalation group and the control group in ambulation, rearing, preening and grooming.

• Molecules and Cells
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• 제41권8호
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• pp.724-732
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• 2018

Plant defence responses to various biotic stresses via systemic acquired resistance (SAR) are induced by avirulent pathogens and chemical compounds, including certain plant hormones in volatile form, such as methyl salicylate and methyl jasmonate. SAR refers to the observation that, when a local part of a plant is exposed to elicitors, the entire plant exhibits a resistance response. In the natural environment, plants are continuously exposed to avirulent pathogens that induce SAR and volatile emissions affecting neighbouring plants as well as the plant itself. However, the underlying mechanism has not been intensively studied. In this study, we evaluated whether plants "memorise" the previous activation of plant immunity when exposed repeatedly to plant defensive volatiles such as methyl salicylate and methyl jasmonate. We hypothesised that stronger SAR responses would occur in plants treated with repeated applications of the volatile plant defence compound MeSA than in those exposed to a single or no treatment. Nicotiana benthamiana seedlings subjected to repeated applications of MeSA exhibited greater protection against Pseudomonas syringae pv. tabaci and Pectobacterium carotovorum subsp. carotovorum than the control. The increase in SAR capacity in response to repeated MeSA treatment was confirmed by analysing the defence priming of the expression of N. benthamiana Pathogenesis-Related 1a (NbPR1a) and NbPR2 by quantitative reverse-transcription PCR compared with the control. We propose the concept of plant memory of plant defence volatiles and suggest that SAR is strengthened by the repeated perception of volatile compounds in plants.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.721-726
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• 2004

A simplified method for the computation of first second and higher order derivatives of eigenvalues and eigenvectors derivatives associated with repeated eigenvalues is presented. Adjacent eigenvectors and orthonormal conditions are used to compose an algebraic equation whose order is (n+m)x(n+m), where n is the number of coordinates and m is the number of multiplicity of the repeated eigenvalues. The algebraic equation developed can be used to compute derivatives of both eigenvalues and eigenvectors simultaneously. Since the coefficient matrix in the proposed algebraic equation is non-singular, symmetric and based on N-space it is numerically stable and very efficient compared to previous methods. This method can be consistently applied to structural systems with structural design parameters and mechanical systems with lumped design parameters. To verify the effectiveness of the proposed method, the finite element model of the cantilever beam is considered.

• 임상간호연구
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• 제17권3호
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• pp.399-410
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• 2011

Purpose: This study was conducted to investigate the incidence of blood hemolysis and repeated blood sampling and to identify factors contributing to hemolysis and repeated blood sampling in the emergency department. Methods: A cross-sectional descriptive design was used. Participants were the patients who came to emergency department and are required a blood sampling for electrolyte level. All blood samples were collected by emergency department nurses and determined for hemolysis by experienced laboratory technologists. Data were analyzed using $x^2$-test, Fisher's exact test, Mann-Whitney u test and Binary Logistic Regression to determine significant differences. Results: A total of 402 valid samples were collected. Of these, 30 blood samples (7.5%) were found to be hemolyzed and 9 (2.2%) to be recollected. Statistically significant factors affecting on hemolysis and repeated blood sampling included the time of bloods sampling (night), the time of tourniquet application, and too-fast blood draw into the test tube. Conclusion: We recommend that nurses who take the blood sampling to consider the findings of the study and take the related factors into account as they set up the standardized care protocol in order for nursing quality improvement.

• 한국컴퓨터정보학회논문지
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• 제24권8호
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• pp.159-166
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• 2019

In this paper, we propose takes network marketing as a starting point for analysis, uses the theory of purchasing behavior and enterprise performance to analyze the network marketing strategy of artistic products, incorporates the practical problems encountered by some artistic products enterprises in Zhejiang Province in network marketing into theoretical research. The theoretical model of network marketing strategy acting on enterprise performance through the intermediary effect of purchasing behavior is constructed. This paper conducted an in-depth survey of three representative core domestic companies engaged in Internet marketing of artistic products, and analyzed the questionnaires of 357 respondents. The initial model was verified by statistical tools such as SPSS and AMOS, and three conclusions were drawn: Firstly, network marketing strategies of different dimensions have different effects on purchasing behavior: pricing strategy and product strategy have significant positive effects on impulse purchasing behavior, but channel strategy has no significant impact on impulse purchasing behavior; Channel strategy and product strategy have a significant positive impact on repeated purchasing behavior, but pricing strategy has no significant impact on repeated purchasing behavior. Second, user purchasing behavior has a significant positive impact on enterprise performance. Third, network marketing strategies of different dimensions have significant direct and positive impact on enterprise performance.

• 식품과학과 산업
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• 제52권1호
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• pp.52-59
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• 2019

본고에서는 제품개발을 위한 소비자 조사에서 반복섭취 설계를 적용하는 접근법에 대해 살펴보았다. 제품에 대한 소비자 기호도는 비교적 역동적으로 변화할 수 있어 1회적 기호도 평가는 신제품에 대한 장기적 기호도 예측에 한계가 있다. 특히 시장이 형성되지 않은 제품군의 신제품에 대한 소비자의 기호도를 측정하기 위해서는 반복섭취 설계가 유용할 수 있다. 식품에 대한 반복섭취 설계는 익숙한 식품보다는 새로운 식품에서의 기호도 형성을 연구하는 것이 효과적이다. 다만 반복섭취 설계에 특성상 비교적 오랜 시간이 소요되기 때문에 실험진행자와 대상자 모두에게 어려운 설계이기도 하다. 향후 장기적인 기호도 변화에 대한 보다 빠르고 정확한 예측이 가능한 실험기법의 개발이 필요한 실정이다.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.139-144
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• 2020

Recently, the electronic equipment industry has become active due to the continuous increase in portable storage media with high-speed information communication, and in particular, the production of SSD(Solid State Drives) for miniaturization of mobile devices and high-speed information communication has increased rapidly. When the SSD is ejecting in the SSD test gender, the necessary ejecting force must be kept constant to have a lifespan applicable to the test device. When the ejecting force increased, it leads to wear of the link for ejecting, which causes a problem in that repeated durability decreases and the ejecting of the SSD becomes impossible. In this paper, the repeated durability test analysis according to the material and the reducing ejecting force design were performed to increase the life of the test gender for SSD inspection. The wear level of the pusher head and ejector was analyzed through repeated durability tests according to the material of the pusher head. The validity of the design was verified through the ejecting force test and repeated durability test of the Test gender, which was designed by carrying out the design to reduce the size and ejecting force of the test gender.