• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.222-226
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• 2010

In this paper we study the consensus problem of SISO (Single-Input Single-Output) linear multi-agent systems under a fixed weighted undirected network communication. The dynamics of each agent can be of any order, while it is constrained to be neutrally stable. Based on a simple root locus argument, we show that the problem at hand is always solvable if the gain and zeros of the dynamic compensator, of which dimension is the same as the number of plant poles on the imaginary axis, are chosen suitably, finally the result is successfully verified by an example.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.121-134
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• 2000

Root conditioning has introduced to dissolve the smear layer and to produce surface demineralization, resulting to exposure of dentin collagen fibril and opening of dentinal tubules. The purpose of the present study was to examine the effect of different concentration and application time of tetracycline-HCL on root conditioning. Total 40 root specimen were prepared from 20 periodontitis-prone human single rooted tooth. The specimen were treated with tetracycline-HCL solution(20mg/ml, 50mg/ml, 100mg/ml)for 20 sec, 3 min, 5 min., and saline for 30 sec. The application method was rubbing method with cotton pellet. Under the scanning electron microscopy(20KV), the extent of smear removal and opening of the dentinal tubules were examined at x 3000. The following results were obtained. 1. Treatment of root specimen with saline did not remove the smear layer and open the dentinal tubules. 2. Treatment of root specimen with different concentration of tetracycline-HCL for 20 sec also did not remove the smear layer completely. 3. Treatment of root specimen with different concentration of tetracycline-HCL for 3 min opened the dentinal tubules and removed smear layer. 4. Treatment of root specimen with 50mg/ml of tetracycline-HCL for 3 min showed collagen fibril within the opened dentinal tubules. In conclusion, the effect of root conditioning with tetracycline-HCL is more dependent on the application time than the application concentration. Root conditioning with 50mg/ml tetracycline-HCL for 3 min is enough for obtaining the periodontal regeneration.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.210-215
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• 1999

The proposed detector is consists of three-phase sinusoidal signal generator and peak detector. This peak detector can detect the peak voltage value at the state of variable frequency. In experi-ment three-phase sinusoidal signals are generated from D/A converter using IBM PC and deliv-ered to the peak detector. Each signals are squared by multiplier and summed up Peak value is the square root of summed value extracted by square root circuit.

• 한국운동역학회지
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• 제24권2호
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• pp.111-119
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• 2014

The purpose of this study was to investigate the effects of localized muscle fatigue and whole body fatigue on postural control during single-leg stance after impairment induced by heel raise and the Harvard step test. Thirty-eight university students (19 men: age, $20.1{\pm}0.2$ yrs; height, $175.0{\pm}5.23cm$; weight, $66.8{\pm}5.6kg$; body mass index, $21.8{\pm}1.7kg/m^2$, 19 women: age, $20.6{\pm}1.1yrs$ ; height, $163.6{\pm}6.7cm$; weight, $58.8{\pm}4.6kg$; body mass index, $22.0{\pm}2.2kg/m^2$) were participated in this study. Subjects performed a series of single-leg postural tasks prior to, following, and 24 hours after completing: heel raise or the Harvard step test. This study showed that the root mean squared distance and velocity in the anteroposterior and mediolateral planes of the center of pressure decreased significantly due to heel raise exercise-induced fatigue. Furthermore, the root mean squared distance in the anteroposterior and mediolateral planes, and the 95% confidence ellipse area of the center of pressure also decreased significantly 24 hours after completing the Harvard step test. In conclusion, this study showed that both heel raise exercise- and Harvard step exercise-induced fatigue affects postural control during single-leg stance in AP and ML planes. Furthermore, this study suggests that changes in the postural control strategy may have occurred after the fatigue protocols during single-leg stance. Also vision can attenuate the postural deficits associated with the fatigues. In order to clarify these results, further studies using other equipment and variables are necessary.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.112.1-112
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• 2003

Genetic diversity of Plasmodiophora brassicae from major chinese cabbage cultivating areas in Korea was analyzed by using PCR-RFLP and RAPD. Single spores of P brassicae isolated from galls of club root made induce lesion on chinese cabbage successfully. The PCR-RFLP and RAPD by primers PbITS, URP 3, 6 and OPA 7 revealed that single spore isolates showed various DNA polymorphisms among them unrelated geographic origins. These results indicate that P. brassicae population in Korea showed genetic difference among them. This study could be facilitate to identify genetic characteristics ofP. brassicae based on DNA polymorphisms between single spore isolates and to get basic information which can be used to advanced resistance breeding against club root of chinese cabbage.

• 조명전기설비학회논문지
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• 제28권11호
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• pp.68-76
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• 2014

This paper presents an offset error compensation algorithm for the accurate phase angle of the grid voltage in single-phase grid-connected inverters. The offset error generated from the grid voltage measurement process cause the fundamental harmonic component with grid frequency in the synchronous reference frame phase lock loop (PLL). As a result, the grid angle is distorted and the power quality in power systems is degraded. In addition, the dq-axis currents in the synchronous reference frame and phase current have the dc component, first and second order ripples compared with the grid frequency under the distorted grid angle. In this paper, the effects of the offset and scaling errors are analyzed based on the synchronous reference frame PLL. Particularly, the offset error can be estimated from the integrator output of the synchronous reference frame PLL and compensated by using proportional-integral controller. Moreover, the RMS (Root Mean Square) function is proposed to detect the offset error component. The effectiveness of the proposed algorithm is verified through simulation and experiment results.

• Restorative Dentistry and Endodontics
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• 제42권2호
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• pp.140-145
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• 2017

Objectives: The aim of this randomized, controlled, prospective clinical study was to evaluate patients' intraoperative discomfort during root canal preparations in which either multi-file rotary (Mtwo) or single-file reciprocating (Reciproc) systems were used. Materials and Methods: Fifty-five adult patients, aged between 25 and 69 years old, with irreversible pulpitis or pulp necrosis participated in this study. Either the mesiobuccal or the distobuccal canals for maxillary molars and either the mesiobuccal or the mesiolingual canals for mandibular molars were randomly chosen to be instrumented with Mtwo multi-file rotary or Reciproc single-file reciprocating systems. Immediately after each canal instrumentation under anesthesia, patient discomfort was assessed using a 1 - 10 visual analog scale (VAS), ranging from 'least possible discomfort' (1) to 'greatest possible discomfort' (10). The Wilcoxon signed-rank test was used to determine significant differences at p < 0.05. Results: Little intraoperative discomfort was found in all cases. No statistically significant differences in intraoperative discomfort between the 2 systems were found (p = 0.660). Conclusions: Root canal preparation with multi-file rotary or single-file reciprocating systems had similar and minimal effects on patients' intraoperative discomfort.

• 대한치과기공학회지
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• 제45권3호
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• pp.74-80
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• 2023

Purpose: This study aimed to evaluate the fit of the anterior and posterior teeth printed using two light-curing three-dimensional (3D) printers. Methods: Anterior and posterior single crowns were designed using dental software and were printed using 2 types of 3D printers, liquid crystal display (LCD) and digital light processing (DLP) (n=40). After the printed crown was scanned again from inside and outside, the prepared teeth were evaluated using a 3D program. To compare the root mean square (RMS) results among groups (α=0.05), the one-way analysis of variance and Tukey's test were used. Results: No statistically significant difference was found between the mean RMS values of the anterior and posterior teeth (p>0.05). However, as a result of comparing the internal, external, and tooth shapes, the DLP group showed significantly low errors in the inner and outer surfaces than LCD group (p<0.05). Conclusion: In terms of clinical acceptance standard of 100 ㎛, the fit of the anterior and posterior teeth fabricated using LCD and DLP was clinically acceptable.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.45-51
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• 2007

This study evaluated the possibility of the 3-dimensional attachment of human periodontal ligament fibroblasts to a periodntally involved root surface after an EDTA treatment in vitro. The human PDL fibroblasts were isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air containing 5% $CO_2$. Eight single-rooted teeth were obtained from patients diagnosed with periodotitis. After scaling and root planing, four teeth were etched with 24% ethylenediaminetetracetic acid (EDTA) for two minutes (Experimental group). The other four teeth were not treated with EDTA and were used as the control group. The human PDL fibroblasts were placed in the total root surface and cultured for 4 weeks. The teeth were fixed in 2.5% glutaraldehyde in PBS before preparation for the scanning electron microscopy (SEM) examination. The human PDL fibroblasts showed a healthy morphology on the root surfaces treated with EDTA (Experimental group) and a relatively unhealthy appearance on the treated root surfaces (Control group). This suggests that EDTA favorably affects the 3-dimensional attachment of human PDL fibroblasts cultured on the root surfaces. which may play an important role in periodontal healing and regeneration.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.8.1-8.8
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• 2023

Objectives: This study was designed to evaluate the parameters of bonding performance to root dentin, including push-out bond strength and dentinal tubular biomineralization, of a hydraulic bioceramic root-end filling material premixed with dimethyl sulfoxide (Endocem MTA Premixed) in comparison to a conventional powder-liquid-type cement (ProRoot MTA). Materials and Methods: The root canal of a single-rooted premolar was filled with either ProRoot MTA or Endocem MTA Premixed (n = 15). A slice of dentin was obtained from each root. Using the sliced specimen, the push-out bond strength was measured, and the failure pattern was observed under a stereomicroscope. The apical segment was divided into halves; the split surface was observed under a scanning electron microscope, and intratubular biomineralization was examined by observing the precipitates formed in the dentinal tubule. Then, the chemical characteristics of the precipitates were evaluated with energy-dispersive X-ray spectroscopic (EDS) analysis. The data were analyzed using the Student's t-test followed by the Mann-Whitney U test (p < 0.05). Results: No significant difference was found between the 2 tested groups in push-out bond strength, and cohesive failure was the predominant failure type. In both groups, flake-shaped precipitates were observed along dentinal tubules. The EDS analysis indicated that the mass percentage of calcium and phosphorus in the precipitate was similar to that found in hydroxyapatite. Conclusions: Regarding bonding to root dentin, Endocem MTA Premixed may have potential for use as an acceptable root-end filling material.