• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.2
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• pp.165-171
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• 2016

A prosthetic knee for above-knee (AK) amputee is categorized into passive and active type. The passive prosthetic knee is generally made by elastic material. Although AK amputee can easily walk by using passive prosthetic leg, knee joint motions are not similar to ordinary persons. The active prosthetic leg can control the knee angle owing to the actuator and microprocessor. However, the active type is not cost-effective and the stability may be lost due to the malfunction of sensors. In order to resolve these disadvantages of passive and active type, a semi-active prosthetic knee which can control the knee angle is proposed in this work. The proposed semi-active one requires a less input energy but provides active type performance. In order to achieve this goal, in this work, a semi-active prosthetic knee using magneto-rheological (MR) damper for AK amputees is designed. The MR damper can support the weight of body by using less energy than actuator of active prosthetic. It can control knee angle by inducing the magnetic field at the time of stance phase. This salient characteristic is evaluated and presented in this work.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.75-84
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• 1994

In general direct-operated pressure reducing valves have been gardly applied to a dynamic control system such as active suspension control because of their poor control stability. But they are more robust than pilot-operated type and do not need pilot control flow. In this paper development of a new direct-operated proportional pressure reducing valve for low-band type active suspension control is reported. By means of a special damper directly linked to the valve spool, the control stability could be effectively improved without drawback in response time. The linearity error was less than $\pm$3.5%. Applied to an experimental active suspension system the new valve showed the $-90^{\circ}$ phase delay at 4Hz with 20% sinusoidal signal input and could control the suspension system with almost same performance as that with a pilot-operated type valve.

• 보존과학연구
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• s.36
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• pp.49-63
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• 2015

In this study, the annual and seasonal concentrations of aldehydes was measured using the active type and passive type method in the temporary exhibition hall and outdoor air. It was compared with the correlation between the methods according the comparison of methods to measured concentrations. As a results, the ${\Sigma}$ aldehydes in exhibition hall by the active type was higher than 6.4 times by passive type. The formaldehyde was exceeded standards in exhibition facilities of the Ministry of Environment. It was the highest concentrations in summer. Annual I/O ratio of formaldehyde was 5.4 and acetaldehyde was 1.9, it was confirmed that a large amount occurs in the temporary exhibition hall. The results of the correlation coefficient and the t-test of formaldehyde were a strong positive linear relationship between the active type and the passive type.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.4
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• pp.722-740
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• 2017

This study was conducted to offer basic data that can be used in a clothing industry for active senior males that are emerging as a new consumer bracket in a rapid aging age. To this end, this study conducted an analysis of 'younger' older male body types based on data from the 6th Size Korea. As a result of the body type analysis of 'younger' older males who are considered active seniors in comparison to 'middle' aged males, the former's height items became shorter compared to 'middle' aged males, but circumference items were bigger. Males aged 35-69, who are 'middle' aged males and 'younger' old males were divided into three body types in this study: Type1- small body type with protruded belly, compared to weight. Type 2- body type of slim torso with wide shoulder-back widths. Type3- big body type overall with tall height and heavy weight. According to body type distribution by age group, the middle-aged males had Type2 body type the most. The younger-old males showed type1 the most. There is a need to reflect the body types of active senior male characteristics in apparel pattern design because the current fits are not appropriate if active senior males wear clothing targeted for males aged 30-50.

• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.12-18
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• 2013

Domestic solar hot water system can be divided into a passive type and an active type. In a passive type the storage tank is horizontally mounted immediately above the solar collectors. No pumping is required as the hot water naturally rises into the storage tank from the collectors through thermo-siphon flow. While, in an active type the storage tank is ground- or floor-mounted and is below the level of the collectors; a circulating pump moves water or heat transfer fluid between the storage tank and the collectors. We installed two types solar hot water systems consisting of the same storage tank and collectors at the same place, and were measured and compared typical operating characteristics under the same external conditions. In particular, the daily system performance was presented through the stirring test after the sunset. The results show that the amount of solar radiation obtained for an active type were less than a passive type on a cloudy day, because the operation of the circulation pump stops frequently took place on that day. However, on a sunny day, depending on the stable operation of the circulation pump, the amount of solar radiation obtained for an active type were increased than a passive type.

• 보존과학연구
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• s.35
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• pp.25-44
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• 2014

In this study, measured annual year and seasonal concentrations of VOCs by Active type and Passive type using the measurement and analysis method in the exhibition hall and outdoor. It was compared with the correlation between the methods according the comparison of methods to measured concentrations. As a results, the annual average concentrations of TVOC in exhibition room($906.5{\mu}g/m^3$) was greater than for most of the study period, more than 1.8 times the standard in the Ministry of Environment. ${\Sigma}VOCs$ concentration of exhibition room by Active type was higher than Passive type. Some VOCs was decreased with the lapse of time a temporary increase tendencies was. The annual average I/O ratio of TVOC was 9.0, ${\Sigma}VOCs$ was confirmed to occur in a large amount inside the exhibition hall ${\Sigma}VOCs$ was studied to 34.0. Correlation coefficient of ${\Sigma}VOCs$ was 0.367. Toluene was 0.567 that the survey was the largest analysis to the relationship between the two methods.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.21-26
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• 2018

In this paper, the switching characteristics of the active clamp type flyback converter, which is deemed suitable for the miniaturization of the external power supply for home appliance, were analyzed and the process of reducing the switching loss was explained. The active clamp type flyback converter operating in the DCM has confirmed that the surge voltage of the main switch does not occur and the turn-off / on loss of the switch do not occur in principle. Also, in the case of the switch for synchronous rectifier, it was showed that the switch current showed half-wave rectified sinusoidal characteristic, and the switching loss was reduced. The switching characteristics of the experimental results gathered from 120 W class prototype were compared with the theoretical waveform in the steady-state and it was confirmed that the power conversion efficiency of the active clamp type flyback converter was maintained high due to the reduction of the switching loss.

• Fashion & Textile Research Journal
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• v.6 no.3
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• pp.367-376
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• 2004

The purpose of this study is to analyze the image evaluation and the preference of tailored jacket focused on the collar's figure according to the body type and the degree of satisfaction with their body of middle-aged women. For this study, twenty seven different types of tailored jacket were designed with some variation of their silhouette, the length and the collar's figure on three hundred and twenty three middle-aged women ranging from 35 to 50 years old. There was a significant difference in the image evaluation and the preference of tailored jacket according to the body type of middleaged women. The women of the type 1 evaluated that portrait lapel collar were the most fascinating, elegant and active, tender and they preferred that style. The women of the type 2 evaluated that breast lapel collar were the most fascinating, elegant and active, tender and they preferred that style. The women of the type 3 evaluated that breast lapel collar were the most fascinating, elegant and active, tender and they preferred that style. The women of the type 4 evaluated that waist lapel collar were the most fascinating, elegant and active, tender and they preferred that style. There was a meaningful difference in the image evaluation and the preference of tailored jacket according to the degree of satisfaction with their bodies. As satisfied with their face size, they thought breast/portrait lapel collar were more attractive, graceful and active, soft and they preferred that style. As satisfied with weight they regarded portrait lapel collar as more attrative, graceful and active, soft and they preferred that style. In this study we found that the middle-aged women evaluated the tailored jacket which was looking esthetic and fitting their body types, as the most attrative, elegant, active, and tender clothing and they prefered that kind of tailored jacket.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.1
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• pp.31-43
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• 2021

In this study, approximate design optimization using various meta-models was performed for the structural design of active type deck support frame. The active type deck support frame was newly developed to facilitate both transportation and installation of 20,000 ton class offshore plant topside. Structural analysis was carried out using the finite element method to evaluate the strength performance of the active type deck support frame in its initial design stage. In the structural analysis, the strength performances were evaluated for various design load conditions that were regulated in ship classification organization. The approximate optimum design problem based on meta-model was formulated such that thickness sizing variables of main structure members were determined by achieving the minimum weight of the active type deck support frame subject to the strength performance constraints. The meta-models used in the approximate design optimization were response surface method, Kriging model, and Chebyshev orthogonal polynomials. The results from approximate design optimization were compared to actual non-approximate design optimization. The Chebyshev orthogonal polynomials among the meta-models used in the approximate design optimization represented the most pertinent optimum design results for the structure design of the active type deck support frame.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.12
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• pp.1176-1182
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• 2010

Vibrations caused by automobile engine are absorbed mostly by a passive-type engine mount. However, user specifications for automobile vibrations require more stringent conditions and higher standard. Hence, active-type engine mount have been developed to cope with such specifications. The active-type engine mount consists of sensor, actuator and controller where a control algorithm is implemented. The performance of the active engine mount depends on the control algorithm if the sensor and actuator satisfies the specification. The control algorithm should be able to suppress persistent vibrations caused by the engine which are related to engine revolution. In this study, three control algorithms are considered for suppressing persistent vibrations, which are the positive position feedback control algorithm, the strain-rate feedback control algorithm, and the modified higher harmonic control algorithm. Experimental results show that all the control algorithms considered in this study are effective in suppressing resonant vibrations but the modified higher harmonic controller is the most effective controller for non-resonant vibrations.