• 대한기계학회논문집A
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• 제27권2호
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• pp.223-230
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• 2003

Stress patterns are created in the plastic spur gear tooth body by introducing a hole or a steel pin to improve stress distribution. Static analysis using finite element method is carried out to show the effect. The result shows that maximum stress as well as tooth tip displacement is dependent on the size and location of a hole or a steel pin. When a hole located on the tooth center line, the maximum static stress level and the tooth tip deflection is always higher than that of a solid gear. But, a considerable reduction in the maximum stress and tooth tip displacement is achieved by insertion of steel pin.

• 소음진동
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• 제5권1호
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• pp.59-65
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• 1995

In this study, we investigated the operational limit of magnetic bearing-rotor system due to the maximum force limit and slew rjate limit of the electromagnetic actuator as a function of the time dependent control characteristics. The feedback gain of the controller varies the current of the electromagnet coil with the motion of the rotor. The distorsion of magnetic force due to the slew rate limit is not occurred jup to 30, 000 rpm in the magnetic bearing that we have a close relation with the rotational speed and vibration level of the rotor and the proportional gain of the controller. Therefore the maximum force limit determines the maximum allowable orbit radius of the magnetic bearing-rotor system. The maximum allowable vibration levels are exponentially decreased according to the increment of rotational speed and proportional gain of the controller.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.168-176
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• 1997

The purpose of this study is to know load for each human body's knee joint to endure load efficiently, when weight lifter pulls suitable bar in the each weight lifting level. To use the difference of load and correlation between men and women, the conclusion of this stduy is to find parameters to conduct maximum limitation of maximum load to search maximum limitation. The moment of each joint in the lower area was to have a much difference between group of the turunk in the first step. It decreased rapidly until decent and greatly pulled in the second step. Neuromusclar moment increased suddenly in the decrease phase. This phenomenon resulted from shock-absorbing function to sbsorb a load from bar.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.354-357
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• 2001

The residual DC properties in the in-plane switching (IPS) liquid crystal displays(LCDs) which have different concentrations of cynao NLCs and different resistivities of fluorine NLCs were studied. We also propose a new residual DC measurement method, named 'light minimum/maximum method'. We confirmed the precision of residual DC measurement by light minimum/maximum method compared with the flicker minimizing method and found that new measurement method of residual DC is better than that of the conventional flicker minimizing method since the resolution level of measurements is in 0.1 V

• 한국농공학회지
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• 제23권2호
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• pp.45-53
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• 1981

Long term precipitation gaging station record (58 years) was analyzed by progressive mean method to compare the estimated effective period of records for computing mean and probable values. Obtained results are as follows: 1. Fifty-eight years precipitation records at Jinju, Gyeong Sang Nam Do was analyzed by double mass analysis method. Result was appeared that the record was consistent with time. 2. The effective period of records for estimating mean values with the departure of 5% or less from the true mean are up to 33 years for annual precipitation, 20 years for annual maximum daily precipitation and 45 years for maximum successive dry days in summer season. 3. To estimate the probable values by Gumbel-Chow method within the departure of 5% level from true value, periods of 51 years, 38 years and 45 years were required for annual precipitation, annual maximum daily precipitation and maximum successive dry days in summer season, respectively.

• 한국기계가공학회지
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• 제20권5호
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• pp.61-68
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• 2021

Movable weirs with multi-stage control are necessary in many Korean rivers to actively control the water storage level. A mesh dependency test was performed to determine the appropriate number of meshes for structural analysis of movable weirs. The standing angles of movable weirs were set to 60°, 45°, 30°, and 15° for stress analysis. The standing angle of 0° was excluded from the analysis because it was unloaded. Changes in the standing angle led to changes in the water depth, maximum pressure, maximum strain, and maximum stress. The maximum average stress and the structural safety of the multi-stage control movable weir were computed and tested using the Ansys FEA software package.

• 자원ㆍ환경경제연구
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• 제26권4호
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• pp.613-639
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• 2017

카리브호수의 카펜타 자원량을 추정하기 위해 최대엔트로피(ME)모델과 분석적 모델이 적용된다. ME모델을 이용하여 25,372톤의 최대지속가능 어획량(MSY)과 MSY의 어획노력량인 109,731의 어획일수(fishing nights)를 추정하였는데, 이는 현재 어획노력량 수준이 과잉투자됨으로써 1988년 이후 2009년 현재까지 자원량을 감소시키는 요인인 것을 나타낸다. 분석적 모델은 매년의 생물학적 허용 어획량(ABC)과 연간 1.21의 어획사망계수(일반적 어획사망계수인 0.927 보다 큰)를 추정한다. 이 두 모델은 1982년 기준년도의 자원량 추정에 적용할 수 있는 유사한 자원량을 추정한다. ME모델에 의하면 1988년의 최대 자원량(156,047톤)에 대해 1/3수준이하 까지 점점 하락하는 결과를 추정하였는데, 이는 최근의 어획량이 MSY 수준 이하이지만 ABC수준보다 높게 나타나 남획된 것을 암시한다. 다시 말해서, 분석적 모델은 ME모델에서의 MSY보다 더 보수적인 ABC를 제공함으로써, 보수적인 어업관리정책(총허용어획량제도, 어획노력감소정책 등)을 적극적으로 고려해야함을 내포하고 있다.

• 대한인간공학회지
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• 제29권6호
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• pp.869-874
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• 2010

The purpose of this study was to analyze the skin conductance level (SCL) induced by unexpected situation which reflected the emotional and cognitional responses during driving. The participants included 57 college graduates; 28 males aged $24.5{\pm}1.3$ with $2.3{\pm}1.5$ years of driving experiences and 29 females aged $23.6{\pm}2.6$ with $2.2{\pm}1.7$ years of driving experience. Reaction time of brake, averaged SCL, maximum SCL, and rising time to maximum amplitude were measured. They were analysed according to condition (crash, non-crash) and gender (male, female). The reaction time of brake was more faster and averaged SCL was greater during non-crash condition than during crash condition. There were no significant differences between male and female drivers in the reaction time of brake and averaged SCL whether or not it crash. There were no significant differences between crash and non-crash conditions in the maximum SCL and rising time to maximum amplitude, but there were significant differences between male and female in them. These results support the hypothesis that averaged SCL is more related to cognitional response and maximum SCL and rising time to maximum amplitude are more related to emotional responses.

• Journal of Plant Biotechnology
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• 제1권2호
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• pp.117-121
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• 1999

Effects of jasmonic acid treatment, UV-B and white light treatment on the anthocyanin biosynthesis and cell growth were investigated using the cell suspension culture system of grape (Vitis vinifera L.). Cell growth was not affected by white light irradiation, while it was remarkably suppressed by UV-B irradiation from 8 to 32 h. Anthocyanin accumulation dramatically increased after 16 h from irradiation of UV-B. Simultaneous treatment of jasmonic acid and UV-B increased anthocyanin accumulation by 10-fold. The cell division was restored when anthocyanin was abundantly accumulated after 32 h from UV-B irradiation. Optimum concentration of jasmonic acid was found to be 5 uM for maximum accumulation of anthocyanin. Application of jasmonic acid to grape suspension cells rapidly induced the expression of CHS gene after 2 h from treatment and showed maximum level at 32 h. Simultaneous treatment of jasmonic acid and light also induced CHS gene expression after 2 h, but the maximum level of CHS transcript was observed at 16 h with white light and 8 h with UV-B exposure. The synergistical effects could be explained by the defense mechanism that UV irradiation is mediated in part by alterations in JA and its signaling pathway.

• Ocean and Polar Research
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• 제39권3호
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• pp.195-203
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• 2017

The purpose of this paper is to estimate the optimal $CO_2$ emission in the maximum economic yield (MEY), maximum sustainable yield (MSY), and open access (OA) using a bioeconomic model. The results are as follows; in the case of $E_{MEY}$, $E_{MSY}$, and $E_{OA}$ levels, $CO_2$ emissions are estimated at $150,704,746CO_2/kg$, $352,211,193CO_2/kg$, and $301,409,492CO_2/kg$ respectively. We show that the $E_{MEY}$ is more efficient than the other levels. That is, the level of $E_{MEY}$ signifies the optimal economic fishing usage as the most economically efficient usage for large purse seine fishery catching mackerel species. The emission of $CO_2$ in $E_{MEY}$ is the lowest level. Also, the impacts of climate changes such as ocean temperature increase, ocean acidification, and the combined impact thereof show that the biomass of mackerel decreases.