• Journal of Preventive Medicine and Public Health
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• 제50권5호
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• pp.303-310
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• 2017

Objectives: The aim of this study was to evaluate socioeconomic inequalities in the prevalence of dental caries among an urban population. Methods: This study was conducted among 2000 people 15-40 years of age living in Kurdistan, Iran in 2015. Using a questionnaire, data were collected by 4 trained dental students. The dependent variable was the decayed, missing, and filled teeth (DMF) index. Using principal component analysis, the socioeconomic status (SES) of families was determined based on their household assets. Inequality was measured using the concentration index; in addition, the Oaxaca analytical method was used to determine the contribution of various determinants to the observed inequality. Results: The concentration index for poor scores on the DMF index was -0.32 (95% confidence interval [CI], -0.40 to -0.36); thus, poor DMF indices had a greater concentration in groups with a low SES (p<0.001). Decomposition analysis showed that the mean prevalence of a poor DMF index was 43.7% (95% CI, 40.4 to 46.9%) in the least privileged group and 14.4% (95% CI, 9.5 to 9.2%) in the most privileged group. It was found that 85.8% of the gap observed between these groups was due to differences in sex, parents' education, and the district of residence. A poor DMF index was less prevalent among people with higher SES than among those with lower SES (odds ratio, 0.31; 95% CI, 0.19 to 0.52). Conclusions: An alarming degree of SES inequality in oral health status was found in the studied community. Hence, it is suggested that inequalities in oral health status be reduced via adopting appropriate policies such as the delivery of oral health services to poorer groups and covering such services in insurance programs.

• Journal of Pharmaceutical Investigation
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• 제41권6호
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• pp.331-336
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• 2011

The instability of hirsutenone (HST), a potential therapeutic candidate for the treatment of atopic dermatitis (AD) and ovarian carcinoma, is one of the main concerns for the development of drug product. In the present study, aqueous stability of HST was investigated by kinetic analysis, and the effect of several factors covering temperature, nitrogen gas ($N_2$) flushing, and selection of proper antioxidant was compared. Cosolvent system composed of distilled water and methanol (9:1 v/v) was used as a vehicle to dissolve HST at the concentration of $200{\mu}g/mL$. Samples of aqueous solution were prepared under the absence or presence of antioxidants, such as ascorbic acid (AA), sodium edetate (EDTA), and ascorbyl palmitate (AP), and subjected for stability test. The degradation of HST in aqueous solution was followed by the first order kinetics with an extremely short half life of less than a week at room temperature, and was accelerated as the temperature increased. $N_2$ flushing brought a little enhancement in stability compared to control solution, but the effect was insufficient. The addition of AA and EDTA (0.1%) significantly enhanced the stability of HST at $40^{\circ}C$, but the addition of AP (0.01%) was limited due to its water insolubility and revealed no promising result. The stability of HST was increased proportionally by the amount of AA added, showing the difference in degree of stabilization as an order of magnitude. Finally, we conclude that HST was stabilized by the addition of a suitable antioxidant, suggesting AA as the most effective stabilizer.

• 해양환경안전학회지
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• 제6권2호
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• pp.1-15
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• 2000

In world trade, the vessel traffic in major routes has been congested due to the rapid increase of cargoes and shipping tonnages. The patterns of vessel traffic have also been complicated and diversified. Therefore it was necessary that the Vessel Traffic Service(VTS) should be established in order to enhance the safety of navigation, to prevent the loss of life and damage to the environment. The first advanced radar surveillance system(LevelIII-VTS) was introduced in Pohang, Korea in 1993 and in 13 other ports later. While the hardware of Korea VTS is equal to that of an advanced country, the software, specially the operation manual, the recruitment and education of VTS operator, and the VTS service area is behind that of Russia, USA, Germany, Hong Kong, Singapore and others. After researching and investigating. the VTS equipment and service area of many countries, and analyzing the IMO regulations relevant to VTS and the traffic pattern and accident of Pohang port, the most efficient VTS service area should be established in Pohang. According to the analysis of the preceding studies and research on VTS, the worldwide VTS areas are recognized under the following conditions: First, the service area should be extended over at least radar coverage taking into account of traffic flow, traffic density, the degree of danger to navigation and harbour condition in order to provide all possible services. Second, the established service area should be subdivided and systematized to render reliable VTS services, such as the allocation of VHF frequency and reporting procedure in each area. In conclusion, the VTS service area of Pohang must be established and operated over 10 miles from shore(radar site) covering the radar coverage, so as to include the area of traffic congestion and high density traffic flow.

• 한국조경학회지
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• 제30권2호
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• pp.1-11
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• 2002

The purpose of this study is to investigate landscape image and define elements of difference in visual preference of bridges on the Han River. To do this end, video was used as a media for the evaluation of the landscape image of 16 bridges on the Han River using a Semantic Differential scale. Data is collected by 50 students from Woosuk University, majoring landscape architecture. Final analysis utilized a total of 704 samples of data. Data is analyzed through descriptive statistics, and spatial image is analyzed by factor analysis algorithm Principle component analysis using Varimax method is applied far extraction and factor rotation. T-test is used to find the difference between the bridge type of preference with the data of factor score. Logistic regression is used to select the factors that influences the visual preference among the image factors. The results of this study can be summarized as follows; The image of whole bridges on the Han River is somewhat orderly, sequential and open. The degree of visual preference of unique bridge type is higher than normal but there are some differences in visual preference within the same type of structure. This suggests that the surrounding landscape is one of the important factor for visual preference. Factors covering the image of bridge are found to be 'aesthetic',　'structure','spatial factor', and 'shape'. Total variance is obtained as 60.4%. The aesthetic variables are the most important factor for visual preference and the structural factor presents no significant difference in visual preference between more preferred and less preferred bridges. Since the collapse of Songsu Bridge, we thought the structural factor is very important but the results of this study suggest that it is more important to consider the aesthetic and spatial factors of the bridge to increase the visual preference when planning and designing bridges. Simulations with more detailed data about surroundings should be utilized practical design.

• 경영과정보연구
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• 제35권3호
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• pp.95-113
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• 2016

본 연구는 유전자은행을 통한 유전자원활용을 극대화하기 위한 맥락에서 유전자은행의 유전자원이용에 대한 만족과 지속적 이용의 정도차이를 판별할 수 있는 요인, 즉 유전자원이용자(=연구자)가 유전자원에 부여하는 유용성 속성을 실증적으로 분석하고자 하였다. 이를 위해 기존문헌 고찰을 통해 연구자들이 유전자원에 부여하는 유용성 속성을 연구 활동에의 부합성, 유용특성정보, 활용가치, 연구 활동의 촉진성, 신규성으로 도출하고, 미생물유전자원을 이용하는 연구자들을 대상으로 유전자원이용정도가 높은 집단과 낮은 집단(유전자원이용에 대한 만족과 지속적 이용에 기초하여 분류)을 판별할 수 있는 유용성 속성의 파악을 위해 판별분석을 수행하였다. 분석결과, 5개의 유용성 속성 중에서 유전자원의 활용가치와 연구 활동에의 부합성이 판별력이 가장 높은 것으로 나타났다. 유용특성정보와 연구 활동의 촉진성은 판별력이 그리 높지 않았으며, 신규성은 판별력이 없는 것으로 나타났다. 본 연구의 결과에 기초하여 유전자원의 활용촉진을 위한 정책적 시사점을 제공하였으며, 본 연구의 한계점과 이를 극복하기 위한 향후 연구방향도 제시하였다.

• 한국조경학회지
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• 제28권5호
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• pp.48-57
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• 2000

This paper is dealing with the fundamental properties of planting concrete, replacing the existing cover concrete on the roof of a building. This study is to find out the physical characteristics of the planting concrete and rearing characteristics of the grass throughout the modeling experimental materials. As the results of the experiment, the physical properties of planting concrete show the following results; when the paste to aggregate ratio is 0.2~ 0.4, voids volume : 30~17%, unit weight: 1,710~2,010kg/m3, compressive strength : 45~145kgf/$\textrm{cm}^2$, its pH is more than 11, but is reduced to the proper degree for planting after being neutralized. Kentucky bluegrass covered with planting concrete is grown well. The planting concrete used with blast furnace slag cement shows a better properties at the height, the width and the covering rate by 1.1cm, 0.5mm and 7%, respectively, than those used with ordinary portland cement. Also, the less the paste to aggregate ratio is, the better the plant grows. The orders of the effects of temperature control are as follows; the system of planting concrete with grass>the system of planting concrete without grass>the system of mixed soil>the existed roof system. In case, the planting concrete is placed to the roofs of buildings instead of normal concrete slab, and a number of favorable effect can be expected such as the improvement os environmental factors, the reduction of construction cost, the saving of energy and the reduction of environment load. The future research on the change of a variety of the aggregate conditions and the application of the practical structures should be made, and also the research of the endurance also be performed.

• 대한전자공학회논문지SD
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• 제39권7호
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• pp.7-15
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• 2002

The digital DBS tuner is designed and implemented in a CMOS process using a direct-conversion architecture that offers a high degree of integration. To generate mathched LO I/Q quadrature signals covering the total input frequency range, a fully integrated ring oscillator is employed. And, to decrease a high level of phase noise of the ring oscillator, a frequency synthesizer is designed using a double loop strucure. This paper proposes and verifies a band selective loop for fast frequency switching time of the double loop frequency synthesizer. The down-conversion mixer with source follower input stages is used for low voltage operation. An experiment implementation of the frequency synthesizer and mixer with integrated a 0.25um CMOS process achieves a switching time of 600us when frequency changes from 950 to 2150MHz. And, the experiment results show a quadrature amplitude mismatch of max. 0.06dB and a quadrature phase mismathc of max. >$3.4^{\circ}$.

• 천문학회보
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• 제42권2호
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• pp.58.1-58.1
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• 2017

The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared spectro-photometric instrument optimized to the first Next Generation of small satellite (NEXTSat-1). The off-axis optics was developed to cover a wide field of view with 2 deg. ${\times}$ 2 deg. as well as a wide wavelength range from 0.95 to $2.5{\mu}m$. Considering the simple alignment scheme, afocal system was adapted in the optical components. The mechanical structures were tested under the space environment. We have obtained the accurate calibration data using our test facilities under the operational condition. After the final integration of flight model into the satellite, the communication with the satellite and the functional test were passed. The NISS will be launched in early 2018. During around 2-year operation, the spectro-photometric survey covering more than 100 square degree will be performed. To achieve the major scientific objectives for the study of the cosmic star formation in local and distant universe, the main observational targets will be nearby galaxies, galaxy clusters, star-forming regions and low background regions. Here, we report the final performance of the flight model of the NISS.

• Mycobiology
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• 제40권3호
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• pp.164-167
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• 2012

The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes ${\times}$ two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the $CO_2$ concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the $CO_2$ concentration was $3.8{\pm}1.3%$, daily mean hyphal growth was $2.3{\pm}0.6mm$ and daily mean weight loss was $0.84{\pm}0.26g$. In the bags with 15 mm diameter holes, the $CO_2$ concentration was $6.0{\pm}1.6%$, daily hyphal growth was $2.8{\pm}0.2mm$ and daily weight loss was $0.86{\pm}0.4g$. The bags with 15 mm holes had a higher $CO_2$ concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing $CO_2$ emissions.

• 펄프종이기술
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• 제40권5호
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• pp.1-10
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• 2008

Synthetic mineral microparticles (SMM) is a patented system which has been developed to promote drainage of water and retention of fine particles during papermaking. It is shown in patents that the SMM system can have advantages in both of drainage and retention, compared with montmorillonite (bentonite), which is one of the most popular materials presently used in this kind of application. Turbidity and gravity drainage time were measured using a Britt-Jar test with representative SMM formulations, in order to confirm the efficacy of SMM covering a wide range of compositions and discover effects of some key variables that have the potential to lead to unexpected advantages in terms of the effectiveness of the microparticles, when used in combination with a cationic polyacrylamide treatment of papermaking furnish. An iron silicate showed highest retention performance, as well as suitably fast drainage time relative to other metal silicate and bentonite. Zinc silicate improved retention and drainage. SMM synthesized from aluminum sulfate ($Al_2(SO_4){_3}$) did not show a benefit in retention and drainage, relative to bentonite. SMM synthesized from aluminum chloride ($AlCl_3$) performed better in drainage and retention than bentonite when the Al/Si ratios were 0.76 and 1.00. It was found that when the Al/Si ratio and neutralization are considered, pH variation due to the change of Al/Si ratio can be a key factor to control the size of primary metal silicate particles and the degree of coagulation of the primary particles.