• Journal of Mechanical Science and Technology
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• 제17권8호
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• pp.1133-1139
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• 2003

In this paper, a numerical algorithm for the kinematic analysis of a multi-link five-point suspension system is presented. The kinematic analysis is carried out in terms of the rectangular Cartesian coordinates of some defined points in the links and at the joints. Geometric constraints are introduced to fix the relative positions between the points belonging to the same rigid body. Position, velocity and acceleration analyses are carried out. The presented formulation in terms or this system of coordinates is simple and involves only elementary mathematics. The results of the kinematic analysis are presented and discussed.

• 한국정밀공학회지
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• 제14권7호
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• pp.137-143
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• 1997

In this study, handling simulation of a passenger car is carried out to see the effects of suspension compliance, roll stabilizef bar and chassis flexibility. The front suspension of the car is a MacPherson strut type and the rear suspension is a multi-link type. The following five DADS models are constructed and compared to verify the effects of suspension compliance and chassis flexibility during lane change. (1) Vdhicle model without hard point compliance and stabilizer, (2) Vehicle model with hard point compoiance, (3) Vehicle model with hard point compliance and stabilizer, (4) Vehicle model with hard point compoiance, stabilizer, and one vibration mode of the chaxxis. (5) Vehicle model with hard point compliance, stabilizer, and three vibration modes of the chassis. The result shows that hard point compliance and stabilizer are significant in roll angle, and the flexibility of the chassis affects the yaw angle and yaw rate.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.550-559
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• 2004

In this paper, a recursive formulation for generating the equations of motion of spatial mechanical systems is presented. The rigid bodies are replaced by a dynamically equivalent constrained system of particles which avoids introducing any rotational coordinates. For the open-chain system, the equations of motion are generated recursively along the serial chains using the concepts of linear and angular momenta Closed-chain systems are transformed to open-chain systems by cutting suitable kinematic joints and introducing cut-joint constraints. The formulation is used to carry out the dynamic analysis of multi-link five-point suspension. The results of the simulation demonstrate the generality and simplicity of the proposed dynamic formulation.

• Environmental Engineering Research
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• 제24권1호
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• pp.63-73
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• 2019

This study suggests a method for calculating the benefits of water pipe renewal based on an estimate of the water supply suspension risk. The proposed method based on five benefit items is more direct and specific than other benefit estimation methods. In addition, a methodology evaluating the economics of pipe renewal based on pipe failure rate is proposed for estimating the optimal renewal point from an economic perspective. By estimating the optimal renewal period based on a yearly benefit cost ratio per pipe in a case study area, it was possible to draft an optimal renewal plan for the subject region from an economic perspective. Compared with other methodologies, a reasonable optimal renewal period was derived from an economic point of view. The result of this study may be used to develop future water pipe renewal plans. Moreover, the proposed methodologies and results derived from this study can be applied to asset management plans.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.394-400
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• 2018

Purpose: This research evaluated five types of nanoparticles to develop a surface-enhanced Raman spectroscopy (SERS) method for the rapid detection of two Bacillus species (Bacillus cereus and Bacillus thuringiensis) that are commonly found on fresh produce, which can cause food poisoning. Methods: Bacterial concentrations were adjusted to a constant turbidity, and a total of $30{\mu}L$ of each Bacillus cell suspension was prepared for each nanoparticle. A point-scan Raman system with laser light source of wavelength 785 nm was used to obtain SERS data. Results: There was no qualitative difference in the SERS data of B. cereus and B. thuringiensis for any of the five nanoparticles. Three gold nanoparticles, stabilized in either citrate buffer or ethanol, showed subtle differences in Raman intensities of two Bacillus species at $877.7cm^{-1}$. Conclusions: Among the three types of nanoparticles, the gold nanoparticles stabilized in citrate buffer showed the lowest standard deviation, followed by gold nanoparticles stabilized in ethanol. This result supports the potential application of gold nanoparticles for SERS-based detection of B. cereus and B. thuringiensis.

• 한국조경학회지
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• 제29권6호
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• pp.11-20
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• 2002

This study aims to discover the landscape image of bridges and their harmonization wish surrounding sceneries. This research utilized the basic study tool of psycho-physics and processed the case study of five types of bridges on the Han-River, Seoul. Twenty-one bridges on Han-River were classified into five categories ; the cable stayed bridge, the arch bridge, the girder bridge, the trust bridge and the suspension bridge. Also, aesthetic elements of the bridges including the form the texture, the color, the scale and the harmony were examined. The questionaires to analysis the image and harmonization with surrounding sceneries were designed using semantic differential scale and 5 point Likert scale. The results of the research were as follows. First, components representing the images of bridge landscape are classified into three types, ‘beauty’, ‘weightfulness’ and ‘friendliness’. Second, the image of each bridge as a whole turns out not to be different from each other but to be different in the context of neighboring sceneries. It was also determined that both the Cable Stayed Bridge type and the Arch Bridge type are the most attractive. But, the former does have a more masculine image, and the latter has a m[n feminine image. Third, the Cable Stayed Bridge and the Arch Bridge were evaluated highly in terms of harmonization with surrounding landscapes, while the Girder Bridge received the lowest evaluation. All of the above results suggest that the bridges should be constructed not only for beauty itself in form, color, texture and scale, but also in harmonization with the surrounding landscape. Lastly, it is desirable to do further research to find out sort specific design principles that exist between bridges and tangible surrounding landscape types.

• 한국환경보건학회지
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• 제42권4호
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• pp.266-273
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• 2016

Objectives: This study evaluated the virucidal efficacy against avian influenza virus (AIV) of a disinfectant spray containing 0.25% grapefruit seed extract, 0.2% citric acid, 0.0625% malic acid and 0.0125% benzalkonium chloride. Methods: The disinfectant spray was diluted several times with hard water (HW) and organic matter (OM). Two point five mL of each diluent was added into each test tube, and 2.5 mL of AIV suspension was inserted into each test tube. After 30 minutes of virus-disinfectant contact reaction at $4^{\circ}C$, 2.5 mL of 10% inactivated fetal bovine serum was added into each test tube to neutralize the sanitizer efficacy. The neutralized solutions were serial 10-fold dilutions with phosphate buffer solution, and 0.2 mL of the diluents was injected into the allantoic cavity of five ten-day-old-chickens per dilution time. After incubation of the embryos for five days, the viability of the AIV was examined by hemagglutination titer. The valid dilution of the disinfectant spray was estimated according to the dilution time that the virus titer was inactivated more than $10^4$ 50% egg-infective dose (EID50)/mL compared with pathogen control. Results: In HW and OM conditions, the valid dilutions of the disinfectant spray against AIV were seven- and three-fold dilutions, respectively. The AIV titer of the pathogen control was more than 6.1 log10EID50/mL, and there was no embryonic toxicity. Conclusion: The present study showed that this disinfectant spray has effective virucidal activity against AIV.

• 한국작물학회지
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• 제50권3호
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• pp.191-196
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• 2005

이 실험은 보리의 붉은곰팡이병에 대한 정밀하고 효율성이 높은 검정체계를 확립하고, 이를 토대로 저항성 품종을 선발하고자 실시하였다. 이를 위해서 온$\cdot$습도 조절이 가능한 붉은곰팡이병 전용 습실 검정상을 제작하여 포트 재배한 식물체에 3개의 다른 접종시기별(출수기, 출수후 3일, 출수후 5일)로 SCK-O4 균주의 분생포자 현탁액 $5.0\times10^5$ macroconidia $mL^{-1}$를 각각 접종하고 4개의 다른 기간 동안 습실처리(1, 3, 5, 7일)를 하여 각 처리별 이병 정도를 평가하였다. 또한 절단이 삭검정법을 통한 대량검정법도 검토하였다. 1. 습실 검정상 내에서의 붉은곰팡이병 발병률은 접종시기에 따라 차이를 보이지 않았으나, 습실처리기간에 따라서는 유의한 차이를 보였다. 2.습실 검정상을 이용한 붉은곰팡이병의 저항성 검정은 출수기에 접종하고 습실 검정상 내에서 7일간 유지하여 판정하는 것이 가장 효율적이었다. 3. 포트검정법과 절단이삭검정법의 검정방법간 발병 정도는 고도로 유의한 정의 상관$(r=0.892^{***})$을 보였다. 4. 저항성 품종은 진광보리, 부흥, Atahualpha92, Chevron-b, Gobernadora-d 및 MNBrite-c 등이 선발되었으며, 이들 품종은 2개의 검정시기에서 일정한 저항성을 나타내었다.