• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.84-89
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• 2012

The purpose of this study was to compare radiation dose and image quality between low-dose (LDP) and standard-dose protocol (SDP). LDP (120 kVp, 30 mAs, 2-mm thickness) and SDP (120 kVp, 180 mAs, 1.2-mm thickness) images obtained from 61 subjects were retrospectively evaluated at level of carina bifurcation, using multi-detector CT (Brilliance 16, Philips Medical Systems). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated at ascending aorta and infraspinatus muscle, from CT number and back-ground noise. Radiation dose from two protocols measured at 5-point using acrylic-phantom, and CT number and noise measured at 4-point using water-phantom. All statistical analysis were performed using SPSS 19.0 program. LDP images showed significantly more noise and a significantly lower SNR and CNR than did SDP images at ascending aorta and infraspinatus muscle. Noise, SNR and CNR were significantly correlated with body mass index (p<0.001). Radiation dose, SNR and CNR from phantom were significant differences between two protocols. LDP showed a significant reduction of radiation dose with a significant change in SNR and CNR compared with SDP. Therefore, exposure dose on LDP in clinical applications needs resetting highly more considering image quality.

• Korean Journal of Social Welfare
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• v.64 no.4
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• pp.209-231
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• 2012

Recently, the many anti- stigma program use the 'mental illness is an illness like any other biogenetic illness' approach. This is based on Weiner's attribution affection theory. However, mental illness is difficult to be applied with attribution affection premise because attributing no blame for mental problem(biogenetic cause) leads to fear and dangerousness. We proposed a modified attribution affection model that explains the relations between biogenetic causal belief and social distance. Our model assumed that attributing personal responsibility for each mental problem leads to anger and social distance. And attributing no blame for mental problem(biogenetic causal belief) reinforces perception of dangerousness and social distance. This study presented typical vignettes of schizophrenia, depression and alcoholism according to the diagnosis criteria of DSM-IV to 768 university students randomly. Path analysis was used to test modified attribution affection model. The major findings are, First our original model modified partially for fit index. So final model assumed that i) The more respondents believed personal responsibility, the more anger, the more anger reaction corresponded closely with more social distance. ii) biogenetic causal beliefs leads to a worsening of dangerousness and perception of dangerousness leads to a increasing of social distance. Second, multi-group analysis was conducted to verify how a modified attribution affection model would be applicable to three groups. The result is that there is no difference among three groups. Finding from this research suggest to change anti-stigma program that use medical model.

• Korean Journal of Optics and Photonics
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• v.25 no.1
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• pp.38-43
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• 2014

An external cavity laser supporting two wavelengths is demonstrated by incorporating polymer waveguide Bragg reflectors and a superluminescent light-emitting diode. An oversized rib waveguide structure and Bragg gratings are designed by using the effective-index and transmission-matrix methods. Bragg gratings with different periods are inscribed on a polymer waveguide through double-exposure laser interferometry. In order to tune the cavity loss affected by the reflectivity of Bragg gratings, a Bragg reflectors with varying length is incorporated. Two-wavelength-mode lasing is achieved for the device consisting of 2-mm long, 537-nm period gratings and 2.2-mm long, 540-nm period gratings; the lasing wavelengths are 1554 nm and 1564 nm, with an output power close to 0 dBm, a 20-dB bandwidth of 0.2 nm, and a side-mode suppression ratio of 45 dB.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.513-518
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• 2009

The purpose of this study was to examine correlation between smoking and gingivitis in boy students targeting 281 students in the 2nd grade for vocational boys' high schools where are located in Cheongju city. As a result of carrying out questionnaire research and oral examination, the following conclusions were obtained. 1. The smoking-experience rate in subjects of this study accounted for 59.4%. The current smoking rate was indicated to be 41.3%. Students' average gingivitis prevalence accounted for 61.5%. Out of those students, the students with experience of smoking accounted for 44.8%. The average gingivitis index was $0.20{\pm}0.27$. Out of those students, the students with experience of smoking were indicated to be $0.29{\pm}0.31$. 2. In case of having experience of smoking, the probability of having gingivitis was high(p = 0.000). The more drinking experience led to the higher gingivitis prevalence(p = 0.010). 3. In the multi-variate analysis, a case of gingivitis prevalence was higher in the group with experience of smoking by 5.5 times(p = 0.000) compared to the non-smoking group. A case that the smoking volume for a day is over 6 pieces was higher by 8.4 times(p = 0.000) compared to the non-smoking group. A case of being over 25 months in the smoking period was higher 13.2 times(p = 0.000) compared to the non-smoking group.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.242-252
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• 2016

A process-based ecosystem model, BIOME-BGC, was applied to simulate seasonal and inter-annual dynamics of carbon and water processes for potential evergreen needleleaf forest (ENF) biome in Korea. Two simulation sites, Milyang and Unljin, were selected to reflect warm-and-dry and cool-and-wet climate regimes, where massive diebacks of pines including Pinus densiflora, P. koraiensis and P thunbergii, were observed in 2009 and 2014, respectively. Standard Precipitation Index (SPI) showed periodic drought occurrence at every 5 years or so for both sites. Since mid-2000s, droughts occurred with hotter climate condition. Among many model variables, Cpool (i.e., a temporary carbon pool reserving photosynthetic compounds before allocations for new tissue production) was identified as a useful proxy variable of tree carbon starvation caused by reduction of gross primary production (GPP) and/or increase of maintenance respiration (Rm). Temporal Cpool variation agreed well with timings of pine tree diebacks for both sites. Though water stress was important, winter- and spring-time warmer temperature also played critical roles in reduction of Cpool, especially for the cool-and-wet Uljin. Shallow soil depth intensified the drought effect, which was, however, marginal for soil depth shallower than 0.5 m. Our modeling analysis implicates seasonal drought and warmer climate can intensify vulnerability of ENF dieback in Korea, especially for shallower soils, in which multi-year continued stress is of concern more than short-term episodic stress.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.507-520
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• 2009

The purpose of this study is to analyze the changes in the housing instability of low-income households through their residential mobility. The concept of housing instability is measured by taking into consideration of housing types, number of moves, period of homelessness, and housing affordability index. The result of this study shows that housing instability of low-income households owned their homes is mainly caused from their old housing built in at least 1980, and that of tenant households is due to the heavy burden of rent-to-income ratio. By using multinominal logit model, the study finds that low-income tenant households are more likely to move upwards as they are man-headed, aged and relatively high-income if we categorize residential mobility into four types: upwards, equivalent, trade-off, and downwards migration. Considering that the share of homeowners moving downwards increases while the share of tenants moving upwards decreases as they reside increasingly nearby Seoul, the study finds that low-income households living in big cities are no better off to improve their residential instability for themselves than the low-incomes in local small and midium cities. Furthermore, both low-income owners and tenants are less likely to move downwards as the ratio of single-family housing in former residence increases. Such finding has a policy implication that government needs to maintain affordable single-family housing stock rather than supplying excessive unaffordable multi-family housing in order to enhance residential instability of low-incomes households.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.323-338
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• 2003

The main memory database systems (MMDBMS) efficiently supports various database applications that require high performance since it employs main memory rather than disk as a primary storage. Recently, it has been increased needs that have the fast data processing as well as the efficient modeling of application requiring for a complicated structure, and conformity to applications that need the strict dta consistency. In MMDBMS, because all the data is located in the main memory, it can support the usable expression methods of data satisfying their needs without performance overhead. The method has the operation to manipulate the data and the constraint such as referential integrity in more detail. The data model consists of this methods is an essential component to decide the expression power of DBMS. In this paper, we discuss about various requests to provide the communication services and propose the data model that support it. The mainly discussed issues are 1) definition of the relationship between tables using the pointer, 2) navigation of the data using the relationship, 3) support of the referential integrity for pointer, 4) support of the uniform processing time for the join, 5) support of the object-oriented concepts, and 6) sharing of an index on multi-tables. We discuss the pointer-based data model that designed to include these issues to efficiently support complication environments.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.556-567
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• 2019

As the number of skyscrapers in micro water grid units such as green building and smart building is increasing in the world, the green building certification system is being implemented to solve problems such as increased demand for water resources and energy. However, researches on the use of sustainable water resources like water reuse and water conservation through linkage and continuous use of water resources, while the power and energy sectors are actively conducting R&D projects in the green building certification system on the micro water grid level. Therefore, this paper analyzes the characteristics and limitations of the water resources sector for the continuous utilization of multiple water sources in the green building certification system, due to the inadequate consideration of sustainability. Then investigates whether various water resources such as constants, nature, and alternative water resources are continuously used in and out of the green building or smart building and complex in the micro water grid unit to suggest evaluation methods and performance evaluation standards.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.419-428
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• 2013

The objectives of this research were to determine ecological characteristics and chemical gradients in two different loach populations-Misgurnus anguillicaudatus ($M_a$) and Koreocobitis rotundicaudata ($K_r$). Eight chemical parameters were compared to test the chemical preferences between the two species. The population of Kr occurred more in better water quality, compared to the $M_a$-population. The $M_a$-population co-occurred more with tolerant species (TS) and omnivores, whereas the $K_r$-population co-occurred more with sensitive species (SS) and insectivores. The differences in the tolerance and trophic composition matched well with the result of stream health assessment, based on the multi-metric model of Index of Biological Integrity (IBI). The IBI value in habitat with the $M_a$-population was "19.6" (range: 8~40) indicating a fair condition, and the IBI values of $K_r$-population was 29.4 (range: 12~40) indicating good condition. Similar results were found in physical habitat health analysis (QHEI). Overall, data analysis showed that the $M_a$-population belong to the tolerant species and $K_r$-population belong to sensitive species in the tolerance classification.

• Journal of Korean society of Dental Hygiene
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• v.8 no.1
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• pp.119-131
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• 2008

This study was peformed in order to find out the relationship between the causing factors and the production of each gas 01 oral malodor, to contribute the oral malodor control at dental clinic as well as to establish the effective application of malodor control project for public oral health program 127 patients from 20 to 40 years old who had been visited for preventive dental cares were participated for the study. Such items as caries status, periodontal status, salivary flow, viscosity, pH. Snyder test, plaque deposit and tongue plaque were checked through the oral examination in order to find out the contributing factors Hydrogen sulfide, Methyl mercaptan, Di-methyl sulfide and Ammonia gas components were checked with Oral-Chroma and Attain, the oral malodor check units. Not only the corelation coefficiencies but also the multi-way variance analysis were calculated between each causing factor and each component of oral malodor gases to estimate the contributing factors of the oral malodor. 1. There was no relationship between the caries status and each component pf the oral malodor such as sulfur compound or Ammonia, both in laboratory test and VAS test (pF0.05). It revealed negative relationship between Hydrogen sulfide and FT(rM-0.1904. pE0.05) as well as the VAS and FT (rM-0.210. pE0.05). S0, it was estimated that the less oral malador was recognized when caries state changed to filled state in Hydrogen sulfide laboratory test or VAS test 2. High relationship was showed between salivary flow and Hydrogen sulfide (rM-0.183, pM0.039), Methyl mercaptan(rM-0.234, p-0.008). Dimethyl sulfide(rM-0.234, pM0.008) and Ammonia(-0.361. pM0.001) gas(pE0.05). 3. There was a high relationship between M-PHP(Modified-Patient Hygiene Performance Index) and tong plaque all kinds of sulfide(rM0.249. pM0.005). Ammonia gas component(rM0.232, pM0.009). 4. It was found that considerable relationship was appeared between the periodontal status and Ammonia gas (rM0.274, pM0.002), so, it should be needed to control Ammonia. Such dental Cares as the prevention or early treatment of periodontal disease and the accelerating the salivary flow as well as reducing the amounts and activities of filament or spiral typed oral micro-organism were recommended for adults, not only for dental care program at the dental clinics but also for public health programs, in order to promote the oral health and quality of file for individual and community peoples.