• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.515-522
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• 1999

Several power factor correction(PFC) circuits are presented to achieve high PF electronic ballast for both v voltage-fed and current-f,어 ek'Ctronic ballast. The proposed PFC circuits use valley-fil[(VF) type DClink s stages modified from the conventional VF circuit to adopt the charge pumping method for PFC operations d during the valley intervals. In voltage-fed ballast, charge pump capacitors are connected with the resonant c capaCltor In current-fed type, the charge pump capacitors are connc'Ctc'Cl with the additional second따y-side of t the power transformer. The measured PF is higher than 0.99 and THD is about 10% for all proposed PFC c circuits. The lamp current CF is also acceptable in the proposed circuits. The proposed circuit is suitable for i implementing cost longrightarroweffective electronic ballast.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.59-64
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• 2022

Vibration is one of the factors that degrades the performance of equipment and measurement equipment used in high-tech industries such as semiconductors and display. The vibration isolator is classified into passive type and active type. The passive vibration isolator has the weakness of insufficient vibration isolation performance in the low frequency band, so an active vibration control system that can overcome these problems is used recently. In this paper, PID controller is used to control the active vibration isolator. Methods for setting the gain of the PID controller include the Zeigler-Nichols method, the pole placement method. These methods have the disadvantage of requiring a lot of time or knowing the system model accurately. This paper proposes the gain auto tuning method of the active vibration isolator applied with the PSO algorithm, which is an optimization algorithm that is easy to implement and has stable convergence performance with low calculations. It is expected that it will be possible to improve vibration isolation performance and reduce the time required for gain tuning by applying the proposed PSO algorithm to the active vibration isolator.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.1 s.41
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• pp.3-21
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• 1992

The main objective of this study was to find out the relationship between life style types and clothing evaluatie criteriria. Social wear was selected according to the defined time, place, and occasion's. The questionnaire was administered to 640 housewives during the fall of 1988. The research problems were as follows: 1. To segment the target according to their life styles, and to profile the characteristics of the categorized life style types. 2. To determine the differences in the clothing evaluatie criteria among the various life style types. The result were as follows: 1. Five life style types were defined. They were the Achievement oriented type, the Active- leisure type, the Material oriented type, Conservative-frugal type, and the Passive-stagnant type. 2. The differences in consumer preferences at the element level evaluative criteria including color, fiber content, fabric construction, fabric design, and classes of clothes among the five life style types were also analyzed revealing partial significance.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.3
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• pp.220-225
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• 2002

In this paper, we suggest a new locomotive mechanism fur self-propelling robotic endoscope which could substitute conventional endoscope. Many researchers proposed inchworm-like mechanism for self-propelling robotic endoscope. But it could not be commercialized because they did not solve the limitation caused by clamping. Therefore, we suggest a new radial-type locomotive mechanism with worm. It can propel itself in any situation and take passive-steering because of radial type. In addition, it can be miniaturized with worm. In this paper, we evaluate the mechanism in the dead pig colon as well as under various environments, and verify the performance fur robotic endoscope.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.988-993
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• 2004

This paper considers corrosion problems in the bolt connection of weathering steel box girder bridge using the external electric type corrosion resistance method which resisted to local corrosion in coated steel surface with contacted air. The weathering steel was created a rust itself in the passive state. but a coated box girder type was easily dew form could be made galvanic cell that accelerated corrosion. so that it was ruled by protection coat with some paint. Therefore, it needed that can be applied the external electric type corrosion resistance method in coated surface. As a result of the test of polarization amount had measured that the weathering steel was higher currents than the general steel by about $5\~10\%$. Therefore. an external electric type corrosion resistance method can be used to protect local corrosion in the coated bolt connection of weathering steel box girders effectively.

• Journal of Acupuncture Research
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• v.23 no.5
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• pp.167-175
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• 2006

Objectives : We studied the effects of Radix Asteris herbal acupuncture solution (RAHAS) on the type I hypersensitivity. Methods : In vivo, we measured compound 48/80 induced active systemic anaphylactic shock, anti-DNP IgE induced passive cutaneous anaphylaxis (PCA) and acetic acid induced microvascular permeability using ICR mice. In vitro, we showed effects on cytotoxicity and ${\beta}$-hexosaminidase release from RBL-2H3 cells. Results : In vivo, RAHAS pretreatments at $BL_{13}$ and optional points inhibited active systemic anaphylactic shock induced by compound 48/80 and microvascular permeability increased by acetic acid. PCA was only inhibited by RAHAS pretreatments at $BL_{13}$. In vitro, RAHAS treatments inhibited ${\beta}$-hexosaminidase release. Conclusion : These results suggest that RAHAS may be beneficial in the prevention of type I hypersensitive inflammatory response.

• Korean Journal of Acupuncture
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• v.23 no.3
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• pp.111-122
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• 2006

Objectives : We studied the effects of Scutellariae Radix pharmacopuncture solution (SRHAS) on the type 1 hypersensitivity. Methods : In vivo, we measured compound 48/80-induced active systemic anaphylactic shock using ICR mice and anti-DNP IgE-induced passive cutaneous anaphylaxis (PCA) using Sprague Dawley rats. In vitro, we showed effects on cytotoxicity and ${\beta}-hexosaminidase$ release from RBL-2H3 cells. Results : In vivo, SRHAS pretreatments (100% or 50%) at BL13 inhibited active systemic anaphylactic shock induced by compound 48/80. PCA was only inhibited by pretreatments of SRHAS at optional points. In vitro, $0.1{\sim}2%$ SRHAS treatments did not affect cell viability while ${\beta}$-hexosaminidase release was significantly inhibited. Conclusions : These results suggest that SRHAS may be beneficial in the inhibition of type I hypersensitive inflammatory response.

• The korean journal of orthodontics
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• v.46 no.2
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• pp.73-80
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• 2016

Objective: The purpose of this study was to investigate the static (SFF) and kinetic frictional forces (KFF) in sliding mechanics of hybrid bracket systems that involve placing a conventional bracket (CB) or active self-ligating bracket (ASLB) on the maxillary anterior teeth (MXAT) and a passive SLB (PSLB) on the maxillary posterior teeth (MXPT). Methods: The samples consisted of two thoroughbred types (group 1, anterior-CB + posterior-CB; group 2, anterior-ASLB + posterior-ASLB) and four hybrid types (group 3, anterior-CB + posterior-PSLB-type 1; group 4, anterior-CB + posterior-PSLB-type 2; group 5, anterior-ASLB + posterior-PSLB-type 1; group 6, anterior-ASLB + posterior-PSLB-type 2) (n = 13 per group). After maxillary dentition alignment and maxillary first premolars removal in the stereolithographically-made typodont system, a $0.019{\times}0.025$-inch stainless steel wire was drawn through the right quadrant of the maxillary arch at 0.5 mm/min for 5 min. The SFF and KFF were measured with a mechanical testing machine and statistical analyses were performed. Results: Four different categories of SFF and KFF were observed among all groups (all p < 0.001). Group 1 demonstrated the highest SFF and KFF; groups 4 and 3 were second and third highest, respectively. The fourth category included groups 2, 5, and 6. Placing PSLBs on the MXPT resulted in significant SFF and KFF reductions in cases with CBs on the MXAT, but not in cases with ASLBs on the MXAT. Conclusions: These data might aid in the development of a hybrid bracket system that enables low-friction sliding of an archwire through the MXPT.

• Journal of Korean Academy of Nursing
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• v.27 no.3
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• pp.673-682
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• 1997

The purpose of this study was to examine the relationship between self-esteem and quality of life (QOL) and between coping type and quality of life (QOL) in mothers of handicapped children and (further to identify the level of self-esteem and quality of life of the subjects. The subjects of this study were the 51 mothers of handicapped children who were registered in two special schools in Taejon. The data were collected using a questionnaire and the period of the data collection was from April 18th to May 26th, 1997. The instruments for this study were Rosenberg's self-esteem scale, Folkman & Lazarus's Ways of Coping Checklist(WCC) and the quality of life scale designed by Ro, You Ja. The results were analyzed using SPSS/PC/sup +/. Data analysis included the descriptive correlational statistics of ANOVA. Pearson Correlational Coefficient, and t-test. The results are as follows : 1. The level of self-esteem showed a mean score 34.51 and the level of QOL, a mean score 137.55. An Active type of coping was used more of fen than a passive one. 2. The level of self-esteem differed according to monthly income and was significantly higher in mothers of children with acquired handicaps than those of children with congenital handicaps. The level of QOL differed according to monthly income. 3. There was a positive correlation between health status and self-esteem(r=.355, p<.05), and between health status and QOL(r=.367, p<.01). 4. Test for hypothesis ; Hypothesis 1, "The higher the level of self-esteem in mothers of handicapped children, the higher their level of quality of life will be. "was supported (r=.755, p<.001) Hypothesis 2, "The QOL level for the active coping group as compared to the passive coping group will be higher. " was not supported.

• Smart Structures and Systems
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• v.8 no.5
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• pp.501-524
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• 2011

Recent studies have discovered that a conventional passive isolation system may suffer from an excessive isolator displacement when subjected to a near-fault earthquake that usually has a long-period velocity pulse waveform. Semi-active isolation using variable friction dampers (VFD), which requires a suitable control law, may provide a solution to this problem. To control the VFD in a semi-active isolation system more efficiently, this paper investigates experimentally the possible use of a control law whose control logic is similar to that of the anti-lock braking systems (ABS) widely used in the automobile industry. This ABS-type controller has the advantages of being simple and easily implemented, because it only requires the measurement of the isolation-layer velocity and does not require system modeling for gain design. Most importantly, it does not interfere with the isolation period, which usually decides the isolation efficiency. In order to verify its feasibility and effectiveness, the ABS-type controller was implemented on a variable-friction isolation system whose slip force is regulated by an embedded piezoelectric actuator, and a seismic simulation test was conducted for this isolation system. The experimental results demonstrate that, as compared to a passive isolation system with various levels of added damping, the semi-active isolation system using the ABS-type controller has the better overall performance when both the far-field and the near-fault earthquakes with different PGA levels are considered.