• 구강회복응용과학지
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• 제21권2호
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• pp.133-142
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• 2005

The purpose of this study was to evaluate interaction of restorative method according to amount of remaining clinical crown length. For the study, sixty healthy mandibular premolars with no dental caries were chosen. Specimens with clinical crown length of 1 mm, 2 mm, 3 mm above the cemento-enamel junction(CEJ) were prepared and root canal treatment was conducted using Ni-Ti rotaty files. Thirty specimens were restored with $LuxaCore^{(R)}$ and thirty were restored with casting posts. All specimens were restored with full coverage crowns and the fracture strength was teseted with the MTS universal testing marchine. The fracture pattern was observed by measuring the distance between CEJ and fracture line. From the results above, the fracture strength seems to be influenced more by amount of remaining clinical crown length than restorative method. Good prognosis could be expected, when more than 2mm of clinical crown length is retained. In the future, the further studies on restorative method, to increase fracture strength of teeth will be necessary.

• 한국치위생학회지
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• 제13권2호
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• pp.211-220
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• 2013

Objectives : This study intended to figure out illegal treatment by unlicensed person in dental area and factors, which were considered as user's position on the basis of the local community investigation of health conditions in chungbuk provinces in 2008. Methods : This study used chi-square test and complex sample design of multi-variate logistic regression analysis to question 12,443 peoples who have experience on illegal dental treatment. Results : Multi-variate logistic regression analysis results showed that factors having related to illegal dental treatment are sex, age, education standards, subjective awareness of oral health condition, drinking experience of lifetime, unmet need of dental treatment, chewing difficulty, use of dentures, experience of scaling and the use of interdental care instrument. Conclusions : As a result of this study, in order to root out illegal dental treatment, we need to expand the breadth of health insurance coverage so that it can reduce the burden of dental expenses. Moreover, we need to set out health service of public oral health to inform the importances of maintaining good oral health and the problems of illegal dental treatment by unlicensed person.

• 대기
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• 제28권2호
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• pp.141-151
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• 2018

The KIAPS global model and data assimilation system were extended to assimilate brightness temperature from the Sondeur $Atmosph{\acute{e}}rique$ du Profil $d^{\prime}Humidit{\acute{e}}$ Intertropicale par $Radiom{\acute{e}}trie$ (SAPHIR) passive microwave water vapor sounder on board the Megha-Tropiques satellite. Quality control procedures were developed to assess the SAPHIR data quality for assimilating clear-sky observations over the ocean, and to characterize observation biases and errors. In the global cycle, additional assimilation of SAPHIR observation shows globally significant benefits for 1.5% reduction of the humidity root-mean-square difference (RMSD) against European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS) analysis. The positive forecast impacts for the humidity and temperature in the experiment assimilating SAPHIR were predominant at later lead times between 96- and 168-hour. Even though its spatial coverage is confined to lower latitudes of $30^{\circ}S-30^{\circ}N$ and the observable variable is humidity, the assimilation of SAPHIR has a positive impact on the other variables over the mid-latitude domain. Verification showed a 3% reduction of the humidity RMSD with assimilating SAPHIR, and moreover temperature, zonal wind and surface pressure RMSDs were reduced up to 3%, 5% and 7% near the tropical and mid-latitude regions, respectively.

• Journal of Periodontal and Implant Science
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• 제39권4호
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• pp.437-441
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• 2009

Purpose: The purpose of this report is to show three cases treated by an intergrated periodontal and restorative dentistry approach. Methods: Three patients with Miller Class Ⅰgingiva recessions associated with cervical lesions were enrolled for treatment. Two patients received a connective tissue graft and resin modified glass ionomer, and one patient was treated with a connective tissue graft, resin restoration. Keratinized gingiva and relative gingival recession were measured. Results: The mean reduction of relative gingival recession was 3.7 mm, and the mean keratinized gingiva increase was 2.5 mm. The percentage of root coverage was 80% in average. No signs of gingival inflammation or bleeding on probing were seen. The patients were satisfied with the final esthetics and had no more dentin hypersensitivity. Conclusions: This report indicates that teeth with Miller ClassⅠ gingival recession associated with cervical lesions can be successfully treated by a connective tissue graft combined with restorative dentistry. However, longitudinal randomized controlled clinical trials must be performed to support this approach.

• ETRI Journal
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• 제35권4호
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• pp.638-643
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• 2013

This paper presents a 5-bit digital step attenuator (DSA) using a commercial 0.18-${\mu}m$ silicon-on-insulator (SOI) process for the wideband phased array antenna. Both low insertion loss and low root mean square (RMS) phase error and amplitude error are achieved employing two attenuation topologies of the switched path attenuator and the switched T-type attenuator. The attenuation coverage of 31 dB with a least significant bit of 1 dB is achieved at DC to 20 GHz. The RMS phase error and amplitude error are less than $2.5^{\circ}$ and less than 0.5 dB, respectively. The measured insertion loss of the reference state is less than 5.5 dB at 10 GHz. The input return loss and output return loss are each less than 12 dB at DC to 20 GHz. The current consumption is nearly zero with a voltage supply of 1.8 V. The chip size is $0.93mm{\times}0.68mm$, including pads. To the best of the authors' knowledge, this is the first demonstration of a low phase error DC-to-20-GHz SOI DSA.

• 응용통계연구
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• 제28권1호
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• pp.75-82
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• 2015

본 연구에서는 민감한 이항특성에 대한 신뢰구간 추정에 직접질문법과 간접질문법을 사용한다. 간접질문법으로 응답자들의 응답부담을 줄여주기 위해서 확률장치를 사용하는 Warner (1965)의 확률화응답기법(RRT)을 고려한다. 두 방법에 의한 신뢰구간을 비교하기 위해서 평가기준으로 평균포함확률(MCP), 평균제곱오차의 제곱근(RMSE), 그리고 평균기대폭(MEW)을 사용한다. 수치적 비교 결과 RRT의 MCP가 명목수준()을 크게 초과하여 보수적이고 MEW도 매우 크다. 따라서 이들을 보완해 주어야 실제적으로 간접질문법의 유용성을 높일 수 있다.

• 대한원격탐사학회지
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• 제24권1호
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• pp.65-78
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• 2008

This study compares the relative accuracy and consistency of four split-window land surface temperature (LST) algorithms (Becker and Li, Kerr et ai., Price, Ulivieri et al.) using 24 sets of Terra (Aqua)/Moderate Resolution Imaging Spectroradiometer (MODIS) data, observed ground grass temperature and air temperature over South Korea. The effective spectral emissivities of two thermal infrared bands have been retrieved by vegetation coverage method using the normalized difference vegetation index. The intercomparison results among the four LST algorithms show that the three algorithms (Becker-Li, Price, and Ulivieri et al.) show very similar performances. The LST estimated by the Becker and Li's algorithm is the highest, whereas that by the Kerr et al.'s algorithm is the lowest without regard to the geographic locations and seasons. The performance of four LST algorithms is significantly better during cold season (night) than warm season (day). And the LST derived from Terra/MODIS is closer to the observed LST than that of Aqua/MODIS. In general, the performances of Becker-Li and Ulivieri et al algorithms are systematically better than the others without regard to the day/night, seasons, and satellites. And the root mean square error and bias of Ulivieri et al. algorithm are consistently less than that of Becker-Li for the four seasons.

• 한국환경복원기술학회지
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• 제22권1호
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• pp.47-59
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• 2019

This study was composed of four treatments [no treatment, phosphate + limestone layer treatment, phosphate + sodium bicarbonate + cement layer treatment, and phosphate + sodium bicarbonate + limestone layer treatment] for figuring out vegetation effects on the acid drainage slope. Treated acid neutralizing techniques were effective for neutralizing acidity and vegetative growth in order of [first: phosphate + sodium bicarbonate + limestone layer treatment, second: phosphate + sodium bicarbonate+cement layer treatment, third: phosphate + limestone layer treatment and fourth: no treatment] on the acid drainage slope. We found out that sodium bicarbonate treatment was additory effect on neutralizing acidity and increasing vegetaive growth besides phosphate and neutralizing layer treatments. In neutralizing layer treatments, Limestone layer was more effective for vegetation and acidity compared to cement layer treatment. Cement layer showed negative initial vegetative growth probably due to high soil hardness and toxicity in spite of acid neutralizing effect. Concerning plants growth characteristics, The surface coverage rates of herbaceous plants, namely as Lotus corniculatus var. japonicus and Coreopsis drummondii L were high in the phosphate + sodium bicarbonate + limestone layer treatment while Festuca arundinacea was high in the phosphate + sodium bicarbonate + cement layer treatment. We also figured out that soil acidity affected more on root than top vegetative growth.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.92-100
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• 2023

Wireless communication technology is becoming increasingly prevalent in smart factories, but the rise in the number of wireless devices can lead to interference in the ISM band and obstacles like metal blocks within the factory can weaken communication signals, creating radio shadow areas that impede information exchange. Consequently, accurately determining the radio communication coverage range is crucial. To address this issue, a Radio Environment Map (REM) can be used to provide information about the radio environment in a specific area. In this paper, a technique for estimating an indoor REM usinga mobile robot and machine learning methods is introduced. The mobile robot first collects and processes data, including the Received Signal Strength Indicator (RSSI) and location estimation. This data is then used to implement the REM through machine learning regression algorithms such as Extra Tree Regressor, Random Forest Regressor, and Decision Tree Regressor. Furthermore, the numerical and visual performance of REM for each model can be assessed in terms of R2 and Root Mean Square Error (RMSE).

• Journal of Periodontal and Implant Science
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• 제27권2호
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• pp.379-394
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• 1997

Several methods have been used for regeneration of tissue lost by periodontal disease. Subepithelial connective tissue graft technique, one of the technniques of mucogingival surgery, is used for the regeneration in esthetic problems such as recession, and denuded root coverage. This study is performed to evaluate the healing process and the regeneration and reattachment of periodontal tissue, including the reconstruction of junctional epithelium, and connective tissue. Alveolar defects in five adult dogs were treated with periodontal surgery and were attained by removing the marginal alveolar bone by $4{\time}3mm$ from CEJ in the labial side of incisors, and root surfaces were planed. The experimental sites were divided into two groups as follows. 1. root planing alone(control group) 2. with connective tissue graft (Experimental Group) In the two groups flaps were positioned and sutured tightly, the healing processes were observed and were histologically compared with each other after 2days, 4days, 1week, 2weeks, 4weeks. The results were obtained as follows : 1. In the two groups blood clots were observed as early as 2 and 4 days, and were resorbed at 1 week. 2. In the two groups moderate inflammation was observed as early as 2 and 4 days, decreased at 1 and 2 weeks, and disappeared at 4 weeks. 3. Junctional Epithelium migration was more significant in the control group, and was restrained by graft materials in the experimental group. 4. Features of connective tissue fiber attachment partially showed the parallel pattern in the two groups from 2 weeks, and entirely from 4weeks. 5. Anastomosis, between graft and connective tissue, appeared from 4 days in the experimental group and the border between them was not discriminated at 4weeks.